ceb and I are members of the Derril Water Solar Park cooperative. We were recently invited to vote on whether the coop should bid for a Contract for Difference, in a government green electricity auction. We ve voted No.

• Green electricity from your mainstream supplier is a lie
• Ripple
• Contracts for Difference
• Ripple and CfD
• Voting No

Green electricity from your mainstream supplier is a lie For a while ceb and I have wanted to contribute directly to green energy provision. This isn t really possible in the mainstream consumer electricy market. Mainstream electricity suppliers 100% green energy tariffs are pure greenwashing. In a capitalist boondoogle, they basically divvy up the electricity so that customers on the (typically more expensive) green tariff get the green electricity, and the other customers get whatever is left. (Of course the electricity is actually all mixed up by the National Grid.) There are fewer people signed up for these tariffs than there is green power generated, so this basically means signing up for a green tariff has no effect whatsoever, other than giving evil people more money. Ripple About a year ago we heard about Ripple. The structure is a little complicated, but the basic upshot is: Ripple promote and manage renewable energy schemes. The schemes themselves are each an individual company; the company is largely owned by a co-operative. The co-op is owned by consumers of electricity in the UK., To stop the co-operative being an purely financial investment scheme, shares ownership is limited according to your electricity usage. The electricity is be sold on the open market, and the profits are used to offset members electricity bills. (One gotcha from all of this is that for this to work your electricity billing provider has to be signed up with Ripple, but ours, Octopus, is.) It seemed to us that this was a way for us to directly cause (and pay for!) the actual generation of green electricity. So, we bought shares in one these co-operatives: we are co-owners of the Derril Water Solar Farm. We signed up for the maximum: funding generating capacity corresponding to 120% of our current electricity usage. We paid a little over 5000 for our shares. Contracts for Difference The UK has a renewable energy subsidy scheme, which goes by the name of Contracts for Difference. The idea is that a renewable energy generation company bids in advance, saying that they ll sell their electricity at Y price, for the duration of the contract (15 years in the current round). The lowest bids win. All the electricity from the participating infrastructure is sold on the open market, but if the market price is low the government makes up the difference, and if the price is high, the government takes the winnings. This is supposedly good for giving a stable investment environment, since the price the developer is going to get now doesn t depends on the electricity market over the next 15 years. The CfD system is supposed to encourage development, so you can only apply before you ve commissioned your generation infrastructure. Ripple and CfD Ripple recently invited us to agree that the Derril Water co-operative should bid in the current round of CfDs. If this goes ahead, and we are one of the auction s winners, the result would be that, instead of selling our electricity at the market price, we ll sell it at the fixed CfD price. This would mean that our return on our investment (which show up as savings on our electricity bills) would be decoupled from market electricity prices, and be much more predictable. They can t tell us the price they d want to bid at, and future electricity prices are rather hard to predict, but it s clear from the accompanying projections that they think we d be better off on average with a CfD. The documentation is very full of financial projections and graphs; other factors aren t really discussed in any detail. The rules of the co-op didn t require them to hold a vote, but very sensibly, for such a fundamental change in the model, they decided to treat it roughly the same way as for a rules change: they re hoping to get 75% Yes votes. Voting No The reason we re in this co-op at all is because we want to directly fund renewable electricity. Participating in the CfD auction would involve us competing with capitalist energy companies for government subsidies. Subsidies which are supposed to encourage the provision of green electricity. It seems to us that participating in this auction would remove most of the difference between what we hoped to do by investing in Derril Water, and just participating in the normal consumer electricity market. In particular, if we do win in the auction, that s probably directly removing the funding and investment support model for other, market-investor-funded, projects. In other words, our buying into Derril Water ceases to be an additional green energy project, changing (in its minor way) the UK s electricity mix. It becomes a financial transaction much more tenously connected (if connected at all) to helping mitigate the climate emergency. So our conclusion was that we must vote against.

comments

In my previous blog post Providing online reference documentation for debputy, I made a point about how debhelper documentation was suboptimal on account of being static rather than online. The thing is that debhelper is not alone in this problem space, even if it is a major contributor to the number of packaging files you have to to know about. If we look at the "competition" here such as Fedora and Arch Linux, they tend to only have one packaging file. While most Debian people will tell you a long list of cons about having one packaging file (such a Fedora's spec file being 3+ domain specific languages "mashed" into one file), one major advantage is that there is only "the one packaging file". You only need to remember where to find the documentation for one file, which is great when you are running on wetware with limited storage capacity. Which means as a newbie, you can dedicate less mental resources to tracking multiple files and how they interact and more effort understanding the "one file" at hand. I started by asking myself how can we in Debian make the packaging stack more accessible to newcomers? Spoiler alert, I dug myself into rabbit hole and ended up somewhere else than where I thought I was going. I started by wanting to scan the debian directory and annotate all files that I could with documentation links. The logic was that if debputy could do that for you, then you could spend more mental effort elsewhere. So I combined debputy's packager provided files detection with a static list of files and I quickly had a good starting point for debputy-based packages.

Linux kernel getting a livepatch whilst running a marathon. Generated with AI.

Livepatch service eliminates the need for unplanned maintenance windows for high and critical severity kernel vulnerabilities by patching the Linux kernel while the system runs. Originally the service launched in 2016 with just a single kernel flavour supported.Over the years, additional kernels were added: new LTS releases, ESM kernels, Public Cloud kernels, and most recently HWE kernels too.Recently livepatch support was expanded for FIPS compliant kernels, Public cloud FIPS compliant kernels, and as well IBM Z (mainframe) kernels. Bringing the total of kernel flavours support to over 60 distinct kernel flavours supported in parallel. The table of supported kernels in the documentation lists the supported kernel flavours ABIs, the duration of individual build's support window, supported architectures, and the Ubuntu release. This work was only possible thanks to the collaboration with the Ubuntu Certified Public Cloud team, engineers at IBM for IBM Z (s390x) support, Ubuntu Pro team, Livepatch server & client teams.It is a great milestone, and I personally enjoy seeing the non-intrusive popup on my Ubuntu Desktop that a kernel livepatch was applied to my running system. I do enable Ubuntu Pro on my personal laptop thanks to the free Ubuntu Pro subscription for individuals.What's next? The next frontier is supporting ARM64 kernels. The Canonical kernel team has completed the gap analysis to start supporting Livepatch Service for ARM64. Upstream Linux requires development work on the consistency model to fully support livepatch on ARM64 processors. Livepatch code changes are applied on a per-task basis, when the task is deemed safe to switch over. This safety check depends mostly on kernel stacktraces. For these checks, CONFIG_HAVE_RELIABLE_STACKTRACE needs to be available in the upstream ARM64 kernel. (see The Linux Kernel Documentation). There are preliminary patches that enable reliable stacktraces on ARM64, however these turned out to be problematic as there are lots of fix revisions that came after the initial patchset that AWS ships with 5.10. This is a call for help from any interested parties. If you have engineering resources and are interested in bringing Livepatch Service to your ARM64 platforms, please reach out to the Canonical Kernel team on the public Ubuntu Matrix, Discourse, and mailing list. If you want to chat in person, see you at FOSDEM next weekend.

For the fifth year in a row, I've asked Soci t de Transport de Montr al, Montreal's transit agency, for the foot traffic data of Montreal's subway. By clicking on a subway station, you'll be redirected to a graph of the station's foot traffic.

• Orange line (top10)
• Green line (top10)
• Blue line
• Yellow line
• Global Top 10

Licences

• The subway map displayed on this page, the original dataset and my modified dataset are licenced under CCO 1.0: they are in the public domain.
• The R code I wrote is licensed under the GPLv3+. It's pretty much the same code as last year. I tweaked last's year converter script and although I had to clean some of the data by hand, it worked pretty well.

While working on hz.tools, I started to move my beamforming code from 2-D (meaning, beamforming to some specific angle on the X-Y plane for waves on the X-Y plane) to 3-D. I ll have more to say about that once I get around to publishing the code as soon as I m sure it s not completely wrong, but in the meantime I decided to write a simple simulator to visually check the beamformer against the textbooks. The results were pretty rad, so I figured I d throw together a post since it s interesting all on its own outside of beamforming as a general topic. I figured I d write this in Rust, since I ve been using Rust as my primary language over at zoo, and it s a good chance to learn the language better. This post won t cover the basics of how phased arrays work or the specifics of calculating the phase offsets for each antenna, but I ll dig into how I wrote a simple simulator and how I wound up checking my phase offsets to generate the renders below.

Assumptions I didn t want to build a general purpose RF simulator, anything particularly generic, or something that would solve for any more than the things right in front of me. To do this as simply (and quickly all this code took about a day to write, including the beamforming math) I had to reduce the amount of work in front of me. Given that I was concerend with visualizing what the antenna pattern would look like in 3-D given some antenna geometry, operating frequency and configured beam, I made the following assumptions: All anetnnas are perfectly isotropic they receive a signal that is exactly the same strength no matter what direction the signal originates from. There s a single point-source isotropic emitter in the far-field (I modeled this as being 1 million meters away 1000 kilometers) of the antenna system. There is no noise, multipath, loss or distortion in the signal as it travels through space. Antennas will never interfere with each other.

2-D Polar Plots The last time I wrote something like this, I generated 2-D GIFs which show a radiation pattern, not unlike the polar plots you d see on a microphone. These are handy because it lets you visualize what the directionality of the antenna looks like, as well as in what direction emissions are captured, and in what directions emissions are nulled out. You can see these plots on spec sheets for antennas in both 2-D and 3-D form. Now, let s port the 2-D approach to 3-D and see how well it works out.

Writing the 3-D simulator As an EM wave travels through free space, the place at which you sample the wave controls that phase you observe at each time-step. This means, assuming perfectly synchronized clocks, a transmitter and receiver exactly one RF wavelength apart will observe a signal in-phase, but a transmitter and receiver a half wavelength apart will observe a signal 180 degrees out of phase. This means that if we take the distance between our point-source and antenna element, divide it by the wavelength, we can use the fractional part of the resulting number to determine the phase observed. If we multiply that number (in the range of 0 to just under 1) by tau, we can generate a complex number by taking the cos and sin of the multiplied phase (in the range of 0 to tau), assuming the transmitter is emitting a carrier wave at a static amplitude and all clocks are in perfect sync.

 let observed_phases: Vec<Complex> = antennas
.iter()
.map( antenna   
let distance = (antenna - tx).magnitude();
let distance = distance - (distance as i64 as f64);
((distance / wavelength) * TAU)
 )
.map( phase  Complex(phase.cos(), phase.sin()))
.collect();

At this point, given some synthetic transmission point and each antenna, we know what the expected complex sample would be at each antenna. At this point, we can adjust the phase of each antenna according to the beamforming phase offset configuration, and add up every sample in order to determine what the entire system would collectively produce a sample as.

 let beamformed_phases: Vec<Complex> = ...;
let magnitude = beamformed_phases
.iter()
.zip(observed_phases.iter())
.map( (beamformed, observed)  observed * beamformed)
.reduce( acc, el  acc + el)
.unwrap()
.abs();

Armed with this information, it s straight forward to generate some number of (Azimuth, Elevation) points to sample, generate a transmission point far away in that direction, resolve what the resulting Complex sample would be, take its magnitude, and use that to create an (x, y, z) point at (azimuth, elevation, magnitude). The color attached two that point is based on its distance from (0, 0, 0). I opted to use the Life Aquatic table for this one. After this process is complete, I have a point cloud of ((x, y, z), (r, g, b)) points. I wrote a small program using kiss3d to render point cloud using tons of small spheres, and write out the frames to a set of PNGs, which get compiled into a GIF. Now for the fun part, let s take a look at some radiation patterns!

1x4 Phased Array The first configuration is a phased array where all the elements are in perfect alignment on the y and z axis, and separated by some offset in the x axis. This configuration can sweep 180 degrees (not the full 360), but can t be steared in elevation at all. Let s take a look at what this looks like for a well constructed 1x4 phased array: And now let s take a look at the renders as we play with the configuration of this array and make sure things look right. Our initial quarter-wavelength spacing is very effective and has some outstanding performance characteristics. Let s check to see that everything looks right as a first test. Nice. Looks perfect. When pointing forward at (0, 0), we d expect to see a torus, which we do. As we sweep between 0 and 360, astute observers will notice the pattern is mirrored along the axis of the antennas, when the beam is facing forward to 0 degrees, it ll also receive at 180 degrees just as strong. There s a small sidelobe that forms when it s configured along the array, but it also becomes the most directional, and the sidelobes remain fairly small.

Long compared to the wavelength (1 ) Let s try again, but rather than spacing each antenna of a wavelength apart, let s see about spacing each antenna 1 of a wavelength apart instead. The main lobe is a lot more narrow (not a bad thing!), but some significant sidelobes have formed (not ideal). This can cause a lot of confusion when doing things that require a lot of directional resolution unless they re compensated for.

Going from ( to 5 ) The last model begs the question - what do things look like when you separate the antennas from each other but without moving the beam? Let s simulate moving our antennas but not adjusting the configured beam or operating frequency. Very cool. As the spacing becomes longer in relation to the operating frequency, we can see the sidelobes start to form out of the end of the antenna system.

2x2 Phased Array The second configuration I want to try is a phased array where the elements are in perfect alignment on the z axis, and separated by a fixed offset in either the x or y axis by their neighbor, forming a square when viewed along the x/y axis. Let s take a look at what this looks like for a well constructed 2x2 phased array: Let s do the same as above and take a look at the renders as we play with the configuration of this array and see what things look like. This configuration should suppress the sidelobes and give us good performance, and even give us some amount of control in elevation while we re at it. Sweet. Heck yeah. The array is quite directional in the configured direction, and can even sweep a little bit in elevation, a definite improvement from the 1x4 above.

Long compared to the wavelength (1 ) Let s do the same thing as the 1x4 and take a look at what happens when the distance between elements is long compared to the frequency of operation say, 1 of a wavelength apart? What happens to the sidelobes given this spacing when the frequency of operation is much different than the physical geometry? Mesmerising. This is my favorate render. The sidelobes are very fun to watch come in and out of existence. It looks absolutely other-worldly.

Going from ( to 5 ) Finally, for completeness' sake, what do things look like when you separate the antennas from each other just as we did with the 1x4? Let s simulate moving our antennas but not adjusting the configured beam or operating frequency. Very very cool. The sidelobes wind up turning the very blobby cardioid into an electromagnetic dog toy. I think we ve proven to ourselves that using a phased array much outside its designed frequency of operation seems like a real bad idea.

Future Work Now that I have a system to test things out, I m a bit more confident that my beamforming code is close to right! I d love to push that code over the line and blog about it, since it s a really interesting topic on its own. Once I m sure the code involved isn t full of lies, I ll put it up on the hztools org, and post about it here and on mastodon.

Review: Thud!, by Terry Pratchett

Series:	Discworld #34
Publisher:	Harper
Copyright:	October 2005
Printing:	November 2014
ISBN:	0-06-233498-0
Format:	Mass market
Pages:	434

Thud! is the 34th Discworld novel and the seventh Watch novel. It is partly a sequel to The Fifth Elephant, partly a sequel to Night Watch, and references many of the previous Watch novels. This is not a good place to start. Dwarfs and trolls have a long history of conflict, as one might expect between a race of creatures who specialize in mining and a race of creatures whose vital organs are sometimes the targets of that mining. The first battle of Koom Valley was the place where that enmity was made concrete and given a symbol. Now that there are large dwarf and troll populations in Ankh-Morpork, the upcoming anniversary of that battle is the excuse for rising tensions. Worse, Grag Hamcrusher, a revered deep-down dwarf and a dwarf supremacist, is giving incendiary speeches about killing all trolls and appears to be tunneling under the city. Then whispers run through the city's dwarfs that Hamcrusher has been murdered by a troll. Vimes has no patience for racial tensions, or for the inspection of the Watch by one of Vetinari's excessively competent clerks, or the political pressure to add a vampire to the Watch over his prejudiced objections. He was already grumpy before the murder and is in absolutely no mood to be told by deep-down dwarfs who barely believe that humans exist that the murder of a dwarf underground is no affair of his. Meanwhile, The Battle of Koom Valley by Methodia Rascal has been stolen from the Ankh-Morpork Royal Art Museum, an impressive feat given that the painting is ten feet high and fifty feet long. It was painted in impressive detail by a madman who thought he was a chicken, and has been the spark for endless theories about clues to some great treasure or hidden knowledge, culminating in the conspiratorial book Koom Valley Codex. But the museum prides itself on allowing people to inspect and photograph the painting to their heart's content and was working on a new room to display it. It's not clear why someone would want to steal it, but Colon and Nobby are on the case. This was a good time to read this novel. Sadly, the same could be said of pretty much every year since it was written. "Thud" in the title is a reference to Hamcrusher's murder, which was supposedly done by a troll club that was found nearby, but it's also a reference to a board game that we first saw in passing in Going Postal. We find out a lot more about Thud in this book. It's an asymmetric two-player board game that simulates a stylized battle between dwarf and troll forces, with one player playing the trolls and the other playing the dwarfs. The obvious comparison is to chess, but a better comparison would be to the old Steve Jackson Games board game Ogre, which also featured asymmetric combat mechanics. (I'm sure there are many others.) This board game will become quite central to the plot of Thud! in ways that I thought were ingenious. I thought this was one of Pratchett's best-plotted books to date. There are a lot of things happening, involving essentially every member of the Watch that we've met in previous books, and they all matter and I was never confused by how they fit together. This book is full of little callbacks and apparently small things that become important later in a way that I found delightful to read, down to the children's book that Vimes reads to his son and that turns into the best scene of the book. At this point in my Discworld read-through, I can see why the Watch books are considered the best sub-series. It feels like Pratchett kicks the quality of writing up a notch when he has Vimes as a protagonist. In several books now, Pratchett has created a villain by taking some human characteristic and turning it into an external force that acts on humans. (See, for instance the Gonne in Men at Arms, or the hiver in A Hat Full of Sky.) I normally do not like this plot technique, both because I think it lets humans off the hook in a way that cheapens the story and because this type of belief has a long and bad reputation in religions where it is used to dodge personal responsibility and dehumanize one's enemies. When another of those villains turned up in this book, I was dubious. But I think Pratchett pulls off this type of villain as well here as I've seen it done. He lifts up a facet of humanity to let the reader get a better view, but somehow makes it explicit that this is concretized metaphor. This force is something people create and feed and choose and therefore are responsible for. The one sour note that I do have to complain about is that Pratchett resorts to some cheap and annoying "men are from Mars, women are from Venus" nonsense, mostly around Nobby's subplot but in a few other places (Sybil, some of Angua's internal monologue) as well. It's relatively minor, and I might let it pass without grumbling in other books, but usually Pratchett is better on gender than this. I expected better and it got under my skin. Otherwise, though, this was a quietly excellent book. It doesn't have the emotional gut punch of Night Watch, but the plotting is superb and the pacing is a significant improvement over The Fifth Elephant. The parody is of The Da Vinci Code, which is both more interesting than Pratchett's typical movie parodies and delightfully subtle. We get more of Sybil being a bad-ass, which I am always here for. There's even some lovely world-building in the form of dwarven Devices. I love how Pratchett has built Vimes up into one of the most deceptively heroic figures on Discworld, but also shows all of the support infrastructure that ensures Vimes maintain his principles. On the surface, Thud! has a lot in common with Vimes's insistently moral stance in Jingo, but here it is more obvious how Vimes's morality happens in part because his wife, his friends, and his boss create the conditions for it to thrive. Highly recommended to anyone who has gotten this far. Rating: 9 out of 10

Photo by Pixabay

Ubuntu systems typically have up to 3 kernels installed, before they are auto-removed by apt on classic installs. Historically the installation was optimized for metered download size only. However, kernel size growth and usage no longer warrant such optimizations. During the 23.10 Mantic Minatour cycle, I led a coordinated effort across multiple teams to implement lots of optimizations that together achieved unprecedented install footprint improvements.

Given a typical install of 3 generic kernel ABIs in the default configuration on a regular-sized VM (2 CPU cores 8GB of RAM) the following metrics are achieved in Ubuntu 23.10 versus Ubuntu 22.04 LTS:

• 2x less disk space used (1,417MB vs 2,940MB, including initrd)

• 3x less peak RAM usage for the initrd boot (68MB vs 204MB)

• 0.5x increase in download size (949MB vs 600MB)

• 2.5x faster initrd generation (4.5s vs 11.3s)

• approximately the same total time (103s vs 98s, hardware dependent)

For minimal cloud images that do not install either linux-firmware or modules extra the numbers are:

• 1.3x less disk space used (548MB vs 742MB)

• 2.2x less peak RAM usage for initrd boot (27MB vs 62MB)

• 0.4x increase in download size (207MB vs 146MB)

Hopefully, the compromise of download size, relative to the disk space & initrd savings is a win for the majority of platforms and use cases. For users on extremely expensive and metered connections, the likely best saving is to receive air-gapped updates or skip updates.

This was achieved by precompressing kernel modules & firmware files with the maximum level of Zstd compression at package build time; making actual .deb files uncompressed; assembling the initrd using split cpio archives - uncompressed for the pre-compressed files, whilst compressing only the userspace portions of the initrd; enabling in-kernel module decompression support with matching kmod; fixing bugs in all of the above, and landing all of these things in time for the feature freeze. Whilst leveraging the experience and some of the design choices implementations we have already been shipping on Ubuntu Core. Some of these changes are backported to Jammy, but only enough to support smooth upgrades to Mantic and later. Complete gains are only possible to experience on Mantic and later.

The discovered bugs in kernel module loading code likely affect systems that use LoadPin LSM with kernel space module uncompression as used on ChromeOS systems. Hopefully, Kees Cook or other ChromeOS developers pick up the kernel fixes from the stable trees. Or you know, just use Ubuntu kernels as they do get fixes and features like these first.

The team that designed and delivered these changes is large: Benjamin Drung, Andrea Righi, Juerg Haefliger, Julian Andres Klode, Steve Langasek, Michael Hudson-Doyle, Robert Kratky, Adrien Nader, Tim Gardner, Roxana Nicolescu - and myself Dimitri John Ledkov ensuring the most optimal solution is implemented, everything lands on time, and even implementing portions of the final solution.

Hi, It's me, I am a Staff Engineer at Canonical and we are hiring https://canonical.com/careers.

Lots of additional technical details and benchmarks on a huge range of diverse hardware and architectures, and bikeshedding all the things below:

• https://lists.ubuntu.com/archives/ubuntu-devel/2023-July/thread.html#42652
• https://lists.ubuntu.com/archives/kernel-team/2023-July/thread.html#141412
• https://lists.ubuntu.com/archives/ubuntu-devel/2023-July/thread.html#42707
• https://discourse.ubuntu.com/t/reduce-initramfs-size-and-speed-up-the-generation-in-ubuntu-23-10/38972
• https://lore.kernel.org/all/20230830155820.138178-1-andrea.righi@canonical.com/
• https://lore.kernel.org/all/20230829123808.325202-1-andrea.righi@canonical.com/
• https://facebook.github.io/zstd/

For questions and comments please post to Kernel section on Ubuntu Discourse.

Review: The Cassini Division, by Ken MacLeod

Series:	Fall Revolution #3
Publisher:	Tor
Copyright:	1998
Printing:	August 2000
ISBN:	0-8125-6858-3
Format:	Mass market
Pages:	305

The Cassini Division is the third book in the Fall Revolution series and a fairly direct sequel (albeit with different protagonists) to The Stone Canal. This is not a good place to start the series. It's impossible to talk about the plot of this book without discussing the future history of this series, which arguably includes some spoilers for The Star Fraction and The Stone Canal. I don't think the direction of history matters that much in enjoying the previous books, but read the first two books of the series before this review if you want to avoid all spoilers. When the Outwarders uploaded themselves and went fast, they did a lot of strange things: an interstellar probe contrary to all known laws of physics, the disassembly of Ganymede, and the Malley Mile, which plays a significant role in The Stone Canal. They also crashed the Earth. This was not entirely their fault. There were a lot of politics, religious fundamentalism, and plagues in play as well. But the storm of viruses broadcast from their transformed Jupiter shut down essentially all computing equipment on Earth, which set off much of the chaos. The results were catastrophic, and also politically transformative. Now, the Solar Union is a nearly unified anarchosocialist society, with only scattered enclaves of non-cooperators left outside that structure. Ellen May Ngewthu is a leader of the Cassini Division, the bulwark that stands between humans and the Outwarders. The Division ruthlessly destroys any remnant or probe that dares rise out of Jupiter's atmosphere, ensuring that the Outwarders, whatever they have become after untold generations of fast evolution, stay isolated to the one planet they have absorbed. The Division is very good at what they do. But there is a potential gap in that line of defense: there are fast folk in storage at the other end of the Malley Mile, on New Mars, and who knows what the deranged capitalists there will do or what forces they might unleash. The one person who knows a path through the Malley Mile isn't talking, so Ellen goes in search of the next best thing: the non-cooperator scientist Isambard Kingdom Malley. I am now thoroughly annoyed at how politics are handled in this series, and much less confused by the frequency with which MacLeod won Prometheus Awards from the Libertarian Futurist Society. Some of this is my own fault for having too high of hopes for political SF, but nothing in this series so far has convinced me that MacLeod is seriously engaging with political systems. Instead, the world-building to date makes the classic libertarian mistake of thinking societies will happily abandon stability and predictability in favor of their strange definition of freedom. The Solar Union is based on what Ellen calls the true knowledge, which is worth quoting in full so that you know what kind of politics we're talking about:

Life is a process of breaking down and using other matter, and if need be, other life. Therefore, life is aggression, and successful life is successful aggression. Life is the scum of matter, and people are the scum of life. There is nothing but matter, forces, space and time, which together make power. Nothing matters, except what matters to you. Might makes right, and power makes freedom. You are free to do whatever is in your power, and if you want to survive and thrive you had better do whatever is in your interests. If your interests conflict with those of others, let the others pit their power against yours, everyone for theirselves. If your interests coincide with those of others, let them work together with you, and against the rest. We are what we eat, and we eat everything. All that you really value, and the goodness and truth and beauty of life, have their roots in this apparently barren soil. This is the true knowledge. We had founded our idealism on the most nihilistic implications of science, our socialism on crass self-interest, our peace on our capacity for mutual destruction, and our liberty on determinism. We had replaced morality with convention, bravery with safety, frugality with plenty, philosophy with science, stoicism with anaesthetics and piety with immortality. The universal acid of the true knowledge had burned away a world of words, and exposed a universe of things. Things we could use.

This is certainly something that some people will believe, particularly cynical college students who love political theory, feeling smarter than other people, and calling their pet theories things like "the true knowledge." It is not even remotely believable as the governing philosophy of a solar confederation. The point of government for the average person in human society is to create and enforce predictable mutual rules that one can use as a basis for planning and habits, allowing you to not think about politics all the time. People who adore thinking about politics have great difficulty understanding how important it is to everyone else to have ignorable government. Constantly testing your power against other coalitions is a sport, not a governing philosophy. Given the implication that this testing is through violence or the threat of violence, it beggars belief that any large number of people would tolerate that type of instability for an extended period of time. Ellen is fully committed to the true knowledge. MacLeod likely is not; I don't think this represents the philosophy of the author. But the primary political conflict in this novel famous for being political science fiction is between the above variation of anarchy and an anarchocapitalist society, neither of which are believable as stable political systems for large numbers of people. This is a bit like seeking out a series because you were told it was about a great clash of European monarchies and discovering it was about a fight between Liberland and Sealand. It becomes hard to take the rest of the book seriously. I do realize that one point of political science fiction is to play with strange political ideas, similar to how science fiction plays with often-implausible science ideas. But those ideas need some contact with human nature. If you're going to tell me that the key to clawing society back from a world-wide catastrophic descent into chaos is to discard literally every social system used to create predictability and order, you had better be describing aliens, because that's not how humans work. The rest of the book is better. I am untangling a lot of backstory for the above synopsis, which in the book comes in dribs and drabs, but piecing that together is good fun. The plot is far more straightforward than the previous two books in the series: there is a clear enemy, a clear goal, and Ellen goes from point A to point B in a comprehensible way with enough twists to keep it interesting. The core moral conflict of the book is that Ellen is an anti-AI fanatic to the point that she considers anyone other than non-uploaded humans to be an existential threat. MacLeod gives the reader both reasons to believe Ellen is right and reasons to believe she's wrong, which maintains an interesting moral tension. One thing that MacLeod is very good at is what Bob Shaw called "wee thinky bits." I think my favorite in this book is the computer technology used by the Cassini Division, who have spent a century in close combat with inimical AI capable of infecting any digital computer system with tailored viruses. As a result, their computers are mechanical non-Von-Neumann machines, but mechanical with all the technology of a highly-advanced 24th century civilization with nanometer-scale manufacturing technology. It's a great mental image and a lot of fun to think about. This is the only science fiction novel that I can think of that has a hard-takeoff singularity that nonetheless is successfully resisted and fought to a stand-still by unmodified humanity. Most writers who were interested in the singularity idea treated it as either a near-total transformation leaving only remnants or as something that had to be stopped before it started. MacLeod realizes that there's no reason to believe a post-singularity form of life would be either uniform in intent or free from its own baffling sudden collapses and reversals, which can be exploited by humans. It makes for a much better story. The sociology of this book is difficult to swallow, but the characterization is significantly better than the previous books of the series and the plot is much tighter. I was too annoyed by the political science to fully enjoy it, but that may be partly the fault of my expectations coming in. If you like chewy, idea-filled science fiction with a lot of unexplained world-building that you have to puzzle out as you go, you may enjoy this, although unfortunately I think you need to read at least The Stone Canal first. The ending was a bit unsatisfying, but even that includes some neat science fiction ideas. Followed by The Sky Road, although I understand it is not a straightforward sequel. Rating: 6 out of 10

A trip full of hitchhiking, beautiful places and welcoming locals.

Day 1: Arrival in Kochi Kochi is a city in the state of Kerala, India. This year s DebConf was to be held in Kochi from 3rd September to 17th of September, which I was planning to attend. My friend Suresh, who was planning to join, told me that 29th August 2023 will be Onam, a major festival of the state of Kerala. So, we planned a Kerala trip before the DebConf. We booked early morning flights for Kochi from Delhi and reached Kochi on 28th August. We had booked a hostel named Zostel in Ernakulam. During check-in, they asked me to fill a form which required signing in using a Google account. I told them I don t have a Google account and I don t want to create one either. The people at the front desk seemed receptive, so I went ahead with telling them the problems of such a sign-in being mandatory for check-in. Anyways, they only took a photo of my passport and let me check-in without a Google account. We stayed in a ten room dormitory, which allowed travellers of any gender. The dormitory room was air-conditioned, spacious, clean and beds were also comfortable. There were two bathrooms in the dormitory and they were clean. Plus, there was a separate dormitory room in the hostel exclusive for females. I noticed that that Zostel was not added in the OpenStreetMap and so, I added it :) . The hostel had a small canteen for tea and snacks, a common sitting area outside the dormitories, which had beds too. There was a separate silent room, suitable for people who want to work.

Dormitory room in Zostel Ernakulam, Kochi.

Beds in Zostel Ernakulam, Kochi.

We had lunch at a nearby restaurant and it was hard to find anything vegetarian for me. I bought some freshly made banana chips from the street and they were tasty. As far as I remember, I had a big glass of pineapple juice for lunch. Then I went to the Broadway market and bought some cardamom and cinnamon for home. I also went to a nearby supermarket and bought Matta brown rice for home. Then, I looked for a courier shop to send the things home but all of them were closed due to Onam festival. After returning to the Zostel, I overslept till 9 PM and in the meanwhile, Suresh planned with Saidut and Shwetank (who met us during our stay in Zostel) to go to a place in Fort Kochi for dinner. I suspected I will be disappointed by lack of vegetarian options as they were planning to have fish. I already had a restaurant in mind - Brindhavan restaurant (suggested by Anupa), which was a pure vegetarian restaurant. To reach there, I got off at Palarivattom metro station and started looking for an auto-rickshaw to get to the restaurant. I didn t get any for more than 5 minutes. Since that restaurant was not added to the OpenStreetMap, I didn t even know how far that was and which direction to go to. Then, I saw a Zomato delivery person on a motorcycle and asked him where the restaurant was. It was already 10 PM and the restaurant closes at 10:30. So, I asked him whether he can drop me off. He agreed and dropped me off at that restaurant. It was 4-5 km from that metro station. I tipped him and expressed my gratefulness for the help. He refused to take the tip, but I insisted and he accepted. I entered the restaurant and it was coming to a close, so many items were not available. I ordered some Kadhai Paneer (only item left) with naan. It tasted fine. Since the next day was Thiruvonam, I asked the restaurant about the Sadya thali menu and prices for the next day. I planned to eat Sadya thali at that restaurant, but my plans got changed later.

Onam sadya menu from Brindhavan restaurant.

Day 2: Onam celebrations Next day, on 29th of August 2023, we had plan to leave for Wayanad. Wayanad is a hill station in Kerala and a famous tourist spot. Praveen suggested to visit Munnar as it is far closer to Kochi than Wayanad (80 km vs 250 km). But I had already visited Munnar in my previous trips, so we chose Wayanad. We had a train late night from Ernakulam Junction (at 23:30 hours) to Kozhikode, which is the nearest railway station from Wayanad. So, we checked out in the morning as we had plans to roam around in Kochi before taking the train. Zostel was celebrating Onam on that day. To opt-in, we had to pay 400 rupees, which included a Sadya Thali and a mundu. Me and Suresh paid the amount and opted in for the celebrations. Sadya thali had Rice, Sambhar, Rasam, Avial, Banana Chips, Pineapple Pachadi, Pappadam, many types of pickels and chutneys, Pal Ada Payasam and Coconut jaggery Pasam. And, there was water too :). Those payasams were really great and I had one more round of them. Later, I had a lot of variety of payasams during the DebConf.

Sadya lined up for serving

Sadya thali served on banana leaf.

So, we hung out in the common room and put our luggage there. We played UNO and had conversations with other travellers in the hostel. I had a fun time there and I still think it is one of the best hostel experiences I had. We made good friends with Saiduth (Telangana) and Shwetank (Uttarakhand). They were already aware about the software like debian, and we had some detailed conversations about the Free Software movement. I remember explaining the difference between the terms Open Source and Free Software . I also told them about the Streetcomplete app, a beginner friendly app to edit OpenStreetMap. We had dinner at a place nearby (named Palaraam), but again, the vegetarian options were very limited! After dinner, we came back to the Zostel and me and Suresh left for Ernakulam Junction to catch our train Maveli Express (16604).

Day 3: Going to Wayanad Maveli Express was scheduled to reach Kozhikode at 03:25 (morning). I had set alarms from 03:00 to 03:30, with the gap of 10 minutes. Every time I woke up, I turned off the alarm. Then I woke up and saw train reaching the Kozhikode station and woke up Suresh for deboarding. But then I noticed that the train is actually leaving the station, not arriving! This means we missed our stop. Now we looked at the next stops and whether we can deboard there. I was very sleepy and wanted to take a retiring room at some station before continuing our journey to Wayanad. The next stop was Quilandi and we checked online that it didn t have a retiring room. So, we skipped this stop. We got off at the next stop named Vadakara and found out no retiring room was available. So, we asked about information regarding bus for Wayanad and they said that there is a bus to Wayanad around 07:00 hours from bus station which was a few kilometres from the railway station. We took a bus for Kalpetta (in Wayanad) at around 07:00. The destination of the buses were written in Malayalam, which we could not read. Once again, the locals helped us to get on to the bus to Kalpetta. Vadakara is not a big city and it can be hard to find people who know good Hindi or English, unlike Kochi. Despite language issues, I had no problem there in navigation, thanks to locals. I mostly spent time sleeping during the bus journey. A few hours later, the bus dropped us at Kalpetta. We had a booking at a hostel in Rippon village. It was 16 km from Kalpetta. On the way, we were treated with beautiful views of nature, which was present everywhere in Wayanad. The place was covered with tea gardens and our eyes were treated with beautiful scenery at every corner.

We were treated with such views during the Wayanad trip.

Rippon village was a very quiet place and I liked the calm atmosphere. This place is blessed by nature and has stunning scenery. I found English was more common than Hindi in Wayanad. Locals were very nice and helped me, even if they didn t know my language.

A road in Rippon.

After catching some sleep at the hostel, I went out in the afternoon. I hitchhiked to reach the main road from the hostel. I bought more spices from a nearby shop and realized that I should have waited for my visit to Wayanad to buy cardamom, which I already bought from Kochi. Then, I was looking for post office to send spices home. The people at the spices shop told me that the nearby Rippon post office was closed by that time, but the post office at Meppadi was open, which was 5 km from there. I went to Meppadi and saw the post office closes at 15:00, but I reached five minutes late. My packing was not very good and they asked me to pack it tighter. There was a shop near the post office and the people there gave me a cardboard and tapes, and helped pack my stuff for the post. By the time I went to the post office again, it was 15:30. But they accepted my parcel for post.

Day 4: Kanthanpara Falls, Zostel Wayanad and Karapuzha Dam Kanthanpara waterfalls were 2 km from the hostel. I hitchhiked to the place from the hostel on a scooty. Entry ticket was worth Rs 40. There were good views inside and nothing much to see except the waterfalls.

Entry to Kanthanpara Falls.

Kanthanpara Falls.

We had a booking at Zostel Wayanad for this day and so we shifted there. Again, as with their Ernakulam branch, they asked me to fill a form which required signing in using Google, but when I said I don t have a Google account they checked me in without that. There were tea gardens inside the Zostel boundaries and the property was beautiful.

A view of Zostel Wayanad.

A map of Wayanad showing tourist places.

A view from inside the Zostel Wayanad property.

Later in the evening, I went to Karapuzha Dam. I witnessed a beautiful sunset during the journey. Karapuzha dam had many activites, like ziplining, and was nice to roam around. Chembra Peak is near to the Zostel Wayanad. So, I was planning to trek to the heart shaped lake. It was suggested by Praveen and looking online, this trek seemed worth doing. There was an issue however. The charges for trek were Rs 1770 for upto five people. So, if I go alone I will have to spend Rs 1770 for the trek. If I go with another person, we split Rs 1770 into two, and so on. The optimal way to do it is to go in a group of five (you included :D). I asked front desk at Zostel if they can connect me with people going to Chembra peak the next day, and they told me about a group of four people planning to go to Chembra peak the next day. I got lucky! All four of them were from Kerala and worked in Qatar.

Day 5: Chembra peak trek The date was 1st September 2023. I woke up early (05:30 in the morning) for the Chembra peak trek. I had bought hiking shoes especially for trekking, which turned out to be a very good idea. The ticket counter opens at 07:00. The group of four with which I planned to trek met me around 06:00 in the Zostel. We went to the ticket counter around 06:30. We had breakfast at shops selling Maggi noodles and bread omlette near the ticket counter. It was a hot day and the trek was difficult for an inexperienced person like me. The scenery was green and beautiful throughout.

Terrain during trekking towards the Chembra peak.

Heart-shaped lake at the Chembra peak.

Me at the heart-shaped lake.

Views from the top of the Chembra peak.

View of another peak from the heart-shaped lake.

While returning from the trek, I found out a shop selling bamboo rice, which I bought and will make bamboo rice payasam out of it at home (I have some coconut milk from Kerala too ;)). We returned to Zostel in the afternoon. I had muscle pain after the trek and it has still not completely disappeared. At night, we took a bus from Kalpetta to Kozhikode in order to return to Kochi.

Day 6: Return to Kochi At midnight of 2nd of September, we reached Kozhikode bus stand. Then we roamed around for something to eat. I didn t find anything vegetarian to eat. No surprises there! Then we went to Kozhikode railway station and looked for retiring rooms, but no luck there. We waited at the station and took the next train to Kochi at 03:30 and reached Ernakulam Junction at 07:30 (half hours before train s scheduled time!). From there, we went to Zostel Fort Kochi and stayed one night there and checked out next morning.

Day 7: Roaming around in Fort Kochi On 3rd of September, we roamed around in Fort Kochi. We visited the usual places - St Francis Church, Dutch Palace, Jew Town, Pardesi Synagogue. I also visited some homestays and the owners were very happy to show their place even when I made it clear that I was not looking for a stay. In the evening, we went to Kakkanad to attend DebConf. The story continues in my DebConf23 blog post.

The status quo Back in 2015, I bought an off-the-shelf NAS, a QNAP TS-453mini, to act as my file store and Plex server. I had previously owned a Synology box, and whilst I liked the Synology OS and experience, the hardware was underwhelming. I loaded up the successor QNAP with four 5TB drives in RAID10, and moved all my files over (after some initial DoA drive issues were handled).

QNAP TS-453mini product photo

That thing has been in service for about 8 years now, and it s been a mixed bag. It was definitely more powerful than the predecessor system, but it was clear that QNAP s OS was not up to the same standard as Synology s perhaps best exemplified by HappyGet 2 , the QNAP webapp for downloading videos from streaming services like YouTube, whose icon is a straight rip-off of StarCraft 2. On its own, meaningless but a bad omen for overall software quality

The logo for QNAP HappyGet 2 and Blizzard s StarCraft 2 side by side

Additionally, the embedded Celeron processor in the NAS turned out to be an issue for some cases. It turns out, when playing back videos with subtitles, most Plex clients do not support subtitles properly instead they rely on the Plex server doing JIT transcoding to bake the subtitles directly into the video stream. I discovered this with some Blu-Ray rips of Game of Thrones some episodes would play back fine on my smart TV, but episodes with subtitled Dothraki speech would play at only 2 or 3 frames per second. The final straw was a ransomware attack, which went through all my data and locked every file below a 60MiB threshold. Practically all my music gone. A substantial collection of downloaded files, all gone. Some of these files had been carried around since my college days digital rarities, or at least digital detritus I felt a real sense of loss at having to replace. This episode was caused by a ransomware targeting specific vulnerabilities in the QNAP OS, not an error on my part. So, I decided to start planning a replacement with:

• A non-garbage OS, whilst still being a NAS-appliance type offering (not an off-the-shelf Linux server distro)
• Full remote management capabilities
• A small form factor comparable to off-the-shelf NAS
• A powerful modern CPU capable of transcoding high resolution video
• All flash storage, no spinning rust

At the time, no consumer NAS offered everything (The Asustor FS6712X exists now, but didn t when this project started), so I opted to go for a full DIY rather than an appliance not the first time I ve jumped between appliances and DIY for home storage.

Selecting the core of the system There aren t many companies which will sell you a small motherboard with IPMI. Supermicro is a bust, so is Tyan. But ASRock Rack, the server division of third-tier motherboard vendor ASRock, delivers. Most of their boards aren t actually compliant Mini-ITX size, they re a proprietary Deep Mini-ITX with the regular screw holes, but 40mm of extra length (and a commensurately small list of compatible cases). But, thankfully, they do have a tiny selection of boards without the extra size, and I stumbled onto the X570D4I-2T, a board with an AMD AM4 socket and the mature X570 chipset. This board can use any AMD Ryzen chip (before the latest-gen Ryzen 7000 series); has built in dual 10 gigabit ethernet; IPMI; four (laptop-sized) RAM slots with full ECC support; one M.2 slot for NVMe SSD storage; a PCIe 16x slot (generally for graphics cards, but we live in a world of possibilities); and up to 8 SATA drives OR a couple more NVMe SSDs. It s astonishingly well featured, just a shame it costs about $450 compared to a good consumer-grade Mini ITX AM4 board costing less than half that. I was so impressed with the offering, in fact, that I crowed about it on Mastodon and ended up securing ASRock another sale, with someone else looking into a very similar project to mine around the same timespan. The next question was the CPU. An important feature of a system expected to run 24/7 is low power, and AM4 chips can consume as much as 130W under load, out of the box. At the other end, some models can require as little as 35W under load the OEM-only GE suffix chips, which are readily found for import on eBay. In their PRO variant, they also support ECC (all non-G Ryzen chips support ECC, but only Pro G chips do). The top of the range 8 core Ryzen 7 PRO 5750GE is prohibitively expensive, but the slightly weaker 6 core Ryzen 5 PRO 5650GE was affordable, and one arrived quickly from Hong Kong. Supplemented with a couple of cheap 16 GiB SODIMM sticks of DDR4 PC-3200 direct from Micron for under $50 a piece, that left only cooling as an unsolved problem to get a bootable test system. The official support list for the X570D4I-2T only includes two rackmount coolers, both expensive and hard to source. The reason for such a small list is the non standard cooling layout of the board instead of an AM4 hole pattern with the standard plastic AM4 retaining clips, it has an Intel 115x hole pattern with a non-standard backplate (Intel 115x boards have no backplate, the stock Intel 115x cooler attaches to the holes with push pins). As such every single cooler compatibility list excludes this motherboard. However, the backplate is only secured with a mild glue with minimal pressure and a plastic prying tool it can be removed, giving compatibility with any 115x cooler (which is basically any CPU cooler for more than a decade). I picked an oversized low profile Thermalright AXP120-X67 hoping that its 120mm fan would cool the nearby MOSFETs and X570 chipset too.

Thermalright AXP120-X67, AMD Ryzen 5 PRO 5650GE, ASRock Rack X570D4I-2T, all assembled and running on a flat surface

Testing up to this point Using a spare ATX power supply, I had enough of a system built to explore the IPMI and UEFI instances, and run MemTest86 to validate my progress. The memory test ran without a hitch and confirmed the ECC was working, although it also showed that the memory was only running at 2933 MT/s instead of the rated 3200 MT/s (a limit imposed by the motherboard, as higher speeds are considered overclocking). The IPMI interface isn t the best I ve ever used by a long shot, but it s minimum viable and allowed me to configure the basics and boot from media entirely via a Web browser.

Memtest86 showing test progress, taken from IPMI remote control window

One sad discovery, however, which I ve never seen documented before, on PCIe bifurcation. With PCI Express, you have a number of lanes which are allocated in groups by the motherboard and CPU manufacturer. For Ryzen prior to Ryzen 7000, that s 16 lanes in one slot for the graphics card; 4 lanes in one M.2 connector for an SSD; then 4 lanes connecting the CPU to the chipset, which can offer whatever it likes for peripherals or extra lanes (bottlenecked by that shared 4x link to the CPU, if it comes down to it). It s possible, with motherboard and CPU support, to split PCIe groups up for example an 8x slot could be split into two 4x slots (eg allowing two NVMe drives in an adapter card NVME drives these days all use 4x). However with a Cezanne Ryzen with integrated graphics, the 16x graphics card slot cannot be split into four 4x slots (ie used for for NVMe drives) the most bifurcation it allows is 8x4x4x, which is useless in a NAS.

Screenshot of PCIe 16x slot bifurcation options in UEFI settings, taken from IPMI remote control window

As such, I had to abandon any ideas of an all-NVMe NAS I was considering: the 16x slot split into four 4x, combined with two 4x connectors fed by the X570 chipset, to a total of 6 NVMe drives. 7.6TB U.2 enterprise disks are remarkably affordable (cheaper than consumer SATA 8TB drives), but alas, I was locked out by my 5650GE. Thankfully I found out before spending hundreds on a U.2 hot swap bay. The NVMe setup would be nearly 10x as fast as SATA SSDs, but at least the SATA SSD route would still outperform any spinning rust choice on the market (including the fastest 10K RPM SAS drives)

Containing the core The next step was to pick a case and power supply. A lot of NAS cases require an SFX (rather than ATX) size supply, so I ordered a modular SX500 unit from Silverstone. Even if I ended up with a case requiring ATX, it s easy to turn an SFX power supply into ATX, and the worst result is you have less space taken up in your case, hardly the worst problem to have. That said, on to picking a case. There s only one brand with any cachet making ITX NAS cases, Silverstone. They have three choices in an appropriate size: CS01-HS, CS280, and DS380. The problem is, these cases are all badly designed garbage. Take the CS280 as an example, the case with the most space for a CPU cooler. Here s how close together the hotswap bay (right) and power supply (left) are:

Internal image of Silverstone CS280 NAS build. Image stolen from ServeTheHome

With actual cables connected, the cable clearance problem is even worse:

Internal image of Silverstone CS280 NAS build. Image stolen from ServeTheHome

Remember, this is the best of the three cases for internal layout, the one with the least restriction on CPU cooler height. And it s garbage! Total hot garbage! I decided therefore to completely skip the NAS case market, and instead purchase a 5.25 -to-2.5 hot swap bay adapter from Icy Dock, and put it in an ITX gamer case with a 5.25 bay. This is no longer a served market 5.25 bays are extinct since nobody uses CD/DVD drives anymore. The ones on the market are really new old stock from 2014-2017: The Fractal Design Core 500, Cooler Master Elite 130, and Silverstone SUGO 14. Of the three, the Fractal is the best rated so I opted to get that one however it seems the global supply of new old stock fully dried up in the two weeks between me making a decision and placing an order leaving only the Silverstone case. Icy Dock have a selection of 8-bay 2.5 SATA 5.25 hot swap chassis choices in their ToughArmor MB998 series. I opted for the ToughArmor MB998IP-B, to reduce cable clutter it requires only two SFF-8611-to-SF-8643 cables from the motherboard to serve all eight bays, which should make airflow less of a mess. The X570D4I-2T doesn t have any SATA ports on board, instead it has two SFF-8611 OCuLink ports, each supporting 4 PCI Express lanes OR 4 SATA connectors via a breakout cable. I had hoped to get the ToughArmor MB118VP-B and run six U.2 drives, but as I said, the PCIe bifurcation issue with Ryzen G chips meant I wouldn t be able to run all six bays successfully.

NAS build in Silverstone SUGO 14, mid build, panels removed

Silverstone SUGO 14 from the front, with hot swap bay installed

Actual storage for the storage server My concept for the system always involved a fast boot/cache drive in the motherboard s M.2 slot, non-redundant (just backups of the config if the worst were to happen) and separate storage drives somewhere between 3.8 and 8 TB each (somewhere from $200-$350). As a boot drive, I selected the Intel Optane SSD P1600X 58G, available for under $35 and rated for 228 years between failures (or 11,000 complete drive rewrite cycles). So, on to the big expensive choice: storage drives. I narrowed it down to two contenders: new-old-stock Intel D3-S4510 3.84TB enterprise drives, at about $200, or Samsung 870 QVO 8TB consumer drives, at about $375. I did spend a long time agonizing over the specification differences, the ZFS usage reports, the expected lifetime endurance figures, but in reality, it came down to price $1600 of expensive drives vs $3200 of even more expensive drives. That s 27TB of usable capacity in RAID-Z1, or 23TB in RAID-Z2. For comparison, I m using about 5TB of the old NAS, so that s a LOT of overhead for expansion.

Storage SSD loaded into hot swap sled

Booting up Bringing it all together is the OS. I wanted an appliance NAS OS rather than self-administering a Linux distribution, and after looking into the surrounding ecosystems, decided on TrueNAS Scale (the beta of the 2023 release, based on Debian 12).

TrueNAS Dashboard screenshot in browser window

I set up RAID-Z1, and with zero tuning (other than enabling auto-TRIM), got the following performance numbers:

	IOPS	Bandwidth
4k random writes	19.3k	75.6 MiB/s
4k random reads	36.1k	141 MiB/s
Sequential writes		2300 MiB/s
Sequential reads		3800 MiB/s

Results using fio parameters suggested by Huawei

And for comparison, the maximum theoretical numbers quoted by Intel for a single drive:

	IOPS	Bandwidth
4k random writes	16k	?
4k random reads	90k	?
Sequential writes		280 MiB/s
Sequential reads		560 MiB/s

Numbers quoted by Intel SSD successors Solidigm.

Finally, the numbers reported on the old NAS with four 7200 RPM hard disks in RAID 10:

	IOPS	Bandwidth
4k random writes	430	1.7 MiB/s
4k random reads	8006	32 MiB/s
Sequential writes		311 MiB/s
Sequential reads		566 MiB/s

Performance seems pretty OK. There s always going to be an overhead to RAID. I ll settle for the 45x improvement on random writes vs. its predecessor, and 4.5x improvement on random reads. The sequential write numbers are gonna be impacted by the size of the ZFS cache (50% of RAM, so 16 GiB), but the rest should be a reasonable indication of true performance. It took me a little while to fully understand the TrueNAS permissions model, but I finally got Plex configured to access data from the same place as my SMB shares, which have anonymous read-only access or authenticated write access for myself and my wife, working fine via both Linux and Windows. And that s it! I built a NAS. I intend to add some fans and more RAM, but that s the build. Total spent: about $3000, which sounds like an unreasonable amount, but it s actually less than a comparable Synology DiskStation DS1823xs+ which has 4 cores instead of 6, first-generation AMD Zen instead of Zen 3, 8 GiB RAM instead of 32 GiB, no hardware-accelerated video transcoding, etc. And it would have been a whole lot less fun!

The final system, powered up

(Also posted on PCPartPicker)

There is a bit of context that needs to be shared before I get to this and would be a long one. For reasons known and unknown, I have a lot of sudden electricity outages. Not just me, all those who are on my line. A discussion with a lineman revealed that around 200+ families and businesses are on the same line and when for whatever reason the electricity goes for all. Even some of the traffic lights don t work. This affects software more than hardware or in some cases, both. And more specifically HDD s are vulnerable. I had bought an APC unit several years for precisely this, but over period of time it just couldn t function and trips also when the electricity goes out. It s been 6-7 years so can t even ask customer service to fix the issue and from whatever discussions I have had with APC personnel, the only meaningful difference is to buy a new unit but even then not sure this is an issue that can be resolved, even with that. That comes to the issue that happens once in a while where the system fsck is unable to repair /home and you need to use an external pen drive for the same. This is my how my hdd stacks up
/ is on dev/sda7 /boot is on /dev/sda6, /boot/efi is on /dev/sda2 and /home is on /dev/sda8 so theoretically, if /home for some reason doesn t work I should be able drop down on /dev/sda7, unmount /dev/sda8, run fsck and carry on with my work. I tried it number of times but it didn t work. I was dropping down on tty1 and attempting the same, no dice as root/superuser getting the barest x-term. So first I tried asking couple of friends who live nearby me. Unfortunately, both are MS-Windows users and both use what are called as company-owned laptops . Surfing on those systems were a nightmare. Especially the number of pop-ups of ads that the web has become. And to think about how much harassment ublock origin has saved me over the years. One of the more interesting bits from both their devices were showing all and any downloads from fosshub was showing up as malware. I dunno how much of that is true or not as haven t had to use it as most software we get through debian archives or if needed, download from github or wherever and run/install it and you are in business. Some of them even get compiled into a good .deb package but that s outside the conversation atm. My only experience with fosshub was few years before the pandemic and that was good. I dunno if fosshub really has malware or malwarebytes was giving false positives. It also isn t easy to upload a 600 MB+ ISO file somewhere to see whether it really has malware or not. I used to know of a site or two where you could upload a suspicious file and almost 20-30 famous and known antivirus and anti-malware engines would check it and tell you the result. Unfortunately, I have forgotten the URL and seeing things from MS-Windows perspective, things have gotten way worse than before. So left with no choice, I turned to the local LUG for help. Fortunately, my mobile does have e-mail and I could use gmail to solicit help. While there could have been any number of live CD s that could have helped but one of my first experiences with GNU/Linux was that of Knoppix that I had got from Linux For You (now known as OSFY) sometime in 2003. IIRC, had read an interview of Mr. Klaus Knopper as well and was impressed by it. In those days, Debian wasn t accessible to non-technical users then and Knoppix was a good tool to see it. In fact, think he was the first to come up with the idea of a Live CD and run with it while Canonical/Ubuntu took another 2 years to do it. I think both the CD and the interview by distrowatch was shared by LFY in those early days. Of course, later the story changes after he got married, but I think that is more about Adriane rather than Knoppix. So Vishal Rao helped me out. I got an HP USB 3.2 32GB Type C OTG Flash Drive x5600c (Grey & Black) from a local hardware dealer around similar price point. The dealer is a big one and has almost 200+ people scattered around the city doing channel sales who in turn sell to end users. Asking one of the representatives about their opinion on stopping electronic imports (apparently more things were added later to the list including all sorts of sundry items from digital cameras to shavers and whatnot.) The gentleman replied that he hopes that it would not happen otherwise more than 90% would have to leave their jobs. They already have started into lighting fixtures (LED bulbs, tubelights etc.) but even those would come in the same ban The main argument as have shared before is that Indian Govt. thinks we need our home grown CPU and while I have no issues with that, as shared before except for RISC-V there is no other space where India could look into doing that. Especially after the Chip Act, Biden has made that any new fabs or any new thing in chip fabrication will only be shared with Five Eyes only. Also, while India is looking to generate about 2000 GW by 2030 by solar, China has an ambitious 20,000 GW generation capacity by the end of this year and the Chinese are the ones who are actually driving down the module prices. The Chinese are also automating their factories as if there s no tomorrow. The end result of both is that China will continue to be the world s factory floor for the foreseeable future and whoever may try whatever policies, it probably is gonna be difficult to compete with them on prices of electronic products. That s the reason the U.S. has been trying so that China doesn t get the latest technology but that perhaps is a story for another day.

HP USB 3.2 Type C OTG Flash Drive x5600c For people who have had read this blog they know that most of the flash drives today are MLC Drives and do not have the longevity of the SLC Drives. For those who maybe are new, this short brochure/explainer from Kingston should enhance your understanding. SLC Drives are rare and expensive. There are also a huge number of counterfeit flash drives available in the market and almost all the companies efforts whether it s Kingston, HP or any other manufacturer, they have been like a drop in the bucket. Coming back to the topic at hand. While there are some tools that can help you to figure out whether a pen drive is genuine or not. While there are products that can tell you whether they are genuine or not (basically by probing the memory controller and the info. you get from that.) that probably is a discussion left for another day. It took me couple of days and finally I was able to find time to go Vishal s place. The journey of back and forth lasted almost 6 hours, with crazy traffic jams. Tells you why Pune or specifically the Swargate, Hadapsar patch really needs a Metro. While an in-principle nod has been given, it probably is more than 5-7 years or more before we actually have a functioning metro. Even the current route the Metro has was supposed to be done almost 5 years to the date and even the modified plan was of 3 years ago. And even now, most of the Stations still need a lot of work to be done. PMC, Deccan as examples etc. still have loads to be done. Even PMT (Pune Muncipal Transport) that that is supposed to do the last mile connections via its buses has been putting half-hearted attempts

Vishal Rao While Vishal had apparently seen me and perhaps we had also interacted, this was my first memory of him although we have been on a few boards now and then including stackexchange. He was genuine and warm and shared 4-5 distros with me, including Knoppix and System Rescue as shared by Arun Khan. While this is and was the first time I had heard about Ventoy apparently Vishal has been using it for couple of years now. It s a simple shell script that you need to download and run on your pen drive and then just dump all the .iso images. The easiest way to explain ventoy is that it looks and feels like Grub. Which also reminds me an interaction I had with Vishal on mobile. While troubleshooting the issue, I was unsure whether it was filesystem that was the issue or also systemd was corrupted. Vishal reminded me of putting fastboot to the kernel parameters to see if I m able to boot without fscking and get into userspace i.e. /home. Although journalctl and systemctl were responding even on tty1 still was a bit apprehensive. Using fastboot was able to mount the whole thing and get into userspace and that told me that it s only some of the inodes that need clearing and there probably are some orphaned inodes. While Vishal had got a mini-pc he uses that a server, downloads stuff to it and then downloads stuff from it. From both privacy, backup etc. it is a better way to do things but then you need to laptop to access it. I am sure he probably uses it for virtualization and other ways as well but we just didn t have time for that discussion. Also a mini-pc can set you back anywhere from 25 to 40k depending on the mini-pc and the RAM and the SSD. And you need either a lappy or an Raspberry Pi with some kinda visual display to interact with the mini-pc. While he did share some of the things, there probably could have been a far longer interaction just on that but probably best left for another day. Now at my end, the system I had bought is about 5-6 years old. At that time it only had 6 USB 2.0 drives and 2 USB 3.0 (A) drives.

The above image does tell of the various form factors. One of the other things is that I found the pendrive and its connectors to be extremely fiddly. It took me number of times fiddling around with it when I was finally able to put in and able to access the pen drive partitions. Unfortunately, was unable to see/use systemrescue but Knoppix booted up fine. I mounted the partitions briefly to see where is what and sure enough /dev/sda8 showed my /home files and folders. Unmounted it, then used $fsck -y /dev/sda8 and back in business. This concludes what happened. Updates Quite a bit was left out on the original post, part of which I didn t know and partly stuff which is interesting and perhaps need a blog post of their own. It s sad I won t be part of debconf otherwise who knows what else I would have come to know.

1. One of the interesting bits that I came to know about last week is the Alibaba T-Head T-Head TH1520 RISC-V CPU and saw it first being demoed on a laptop and then a standalone tablet. The laptop is an interesting proposition considering Alibaba opened up it s chip thing only couple of years ago. To have an SOC within 18 months and then under production for lappies and tablets is practically unheard of especially of a newbie/startup. Even AMD took 3-4 years for its first chip.It seems they (Alibaba) would be parceling them out by quarter end 2023 and another 1000 pieces/Units first quarter next year, while the scale is nothing compared to the behemoths, I think this would be more as a matter of getting feedback on both the hardware and software. The value proposition is much better than what most of us get, at least in India. For example, they are doing a warranty for 5 years and also giving spare parts. RISC-V has been having a lot of resurgence in China in part as its an open standard and partly development will be far cheaper and faster than trying x86 or x86-64. If you look into both the manufacturers, due to monopoly, both of them now give 5-8% increment per year, and if you look back in history, you would find that when more chips were in competition, they used to give 15-20% performance increment per year.

2. While Vishal did share with me what he used and the various ways he uses the mini-pc, I did have a fun speculating on what he could use it. As shared by Romane as his case has shared, the first thing to my mind was backups. Filesystems are notorious in the sense they can be corrupted or can be prone to be corrupted very easily as can be seen above . Backups certainly make a lot of sense, especially rsync. The other thing that came to my mind was having some sort of A.I. and chat server. IIRC, somebody has put quite a bit of open source public domain data in debian servers that could be used to run either a chatbot or an A.I. or both and use that similar to how chatGPT but with much limited scope than what chatgpt uses. I was also thinking a media server which Vishal did share he does. I may probably visit him sometime to see what choices he did and what he learned in the process, if anything. Another thing that could be done is just take a dump of any of commodity markets or any markets and have some sort of predictive A.I. or whatever. A whole bunch of people have scammed thousands of Indian users on this, but if you do it on your own and for your own purposes to aid you buy and sell stocks or whatever commodity you may fancy. After all, nowadays markets themselves are virtual. While Vishal s mini-pc doesn t have any graphics, if it was an AMD APU mini-pc, something like this he could have hosted games in the way of thick server, thin client where all graphics processing happens on the server rather than the client. With virtual reality I think the case for the same case could be made or much more. The only problem with VR/AR is that we don t really have mass-market googles, eye pieces or headset. The only notable project that Google has/had in that place is the Google VR Cardboard headset and the experience is not that great or at least was not that great few years back when I could hear and experience the same. Most of the VR headsets say for example the Meta Quest 2 is for around INR 44k/- while Quest 3 is INR 50k+ and officially not available. As have shared before, the holy grail of VR would be when it falls below INR 10k/- so it becomes just another accessory, not something you really have to save for. There also isn t much content on that but then that is also the whole chicken or egg situation. This again is a non-stop discussion as so much has been happening in that space it needs its own blog post/article whatever. Till later.

Consent, Violence, Sexual Abuse This again would be somewhat of a mature post. So children, please refrain from reading. When I hear the above words, my first thought goes to Aamir Khan s Season 1 Episode 2 in Satyamev Jayate. This was the first time that the topic of child sexual abuse was bought in the forefront in the hall rather than a topic to be discussed in the corner. Unfortunately, that episode is still in Hindi and no English subtitles available even today shows a lack of sensitivity in Indian s part to still come to terms with Child abuse that happens in India. The numbers that they had shared at that time were shocking. More than 50 per cent children experience sexual abuse and mostly from friends or relatives. That means 1 in every 2 children. And this was in 2012. But the problem of child sexual abuse didn t start then, it started in the 1960 s, 70 s. In the 1960 s, 1970s we didn t have much of cinema and TV and whatever there was pretty limited. There were few B movie producers, but most of them came into their own in the 1980s. So what influenced Indians in those days were softcore magazines that either had a mature aunt or a teen and they would tease and sooner or later the man would sort of overpower them and fulfill his needs. Even mainstream Indian cinema used similar tropes. One of the most memorable songs of that era Wada Karo Nahi Chodoge Tum Meera Saath from Aa Gale Lag jaa. A bit of context for the song. This is where Shashi Kapoor sees, he tries to ask her to date him, she says no. He tries to put an act where he shows he can t skate or rather pretends. And kinda takes a promise from her that she will date him if he is able to skate. And viola, the next moment he is not just skating, but dancing and singing as well. And the whole he touches her and you can see that is uncomfortable and yet after a while he woos her. Now this is problematic today because we are seeing it from today s lens. It might also have problematic with the feminists of that time, but they probably would have been called overly sensitive or something like that. And this is what went in Universal cinema. But this is just tip of the surface. There were and are multiple poems and even art in those times that flirted and even sort of engaged with sexual molestation, rape both in poems as well as literature, both in Hindi and various regional literature. Similar to stuff that Keats and some other poets (problematic stuff) they wrote and where both men and women were in two minds, whether to take all the other good literature out or kinda make the difference between the art and artist. Now, while Aamir spoke about consent it wasn t in any official capacity or even a legal capacity. The interesting thing was that there was an Act that kinda put some safeguards but had been doing rounds for almost a decade. Because the extremists on both sides, Hindus and Muslims were not in favor of that Act, it was still doing rounds. Aamir s episode on 6th May 2012 and the discussions in mainstream media following that forced the Indian legislature to make POSCO as a law on 22nd May 2012. Almost 6 months to 2 weeks, Nirbhaya happened and changes to the law happened in another 6 months. Both voyeurism and stalking were made jailable offenses and consent became part of lingua franca in the Supreme Court. Couple of weeks back, I had shared in the Manipur case the part about fingering . In the same Act, another change that was done that insertion of any part including foreign objects in any of the openings would be classed as rape . So in that Manipur case, at least those 2-3 people who have been identified as clear perpetrators according to the law of land would be rapists and should have the highest punishment. Unfortunately, the system is rigged against women as Vrinda Grover had shared just couple of weeks back. How a 6 month fast track case (to be completed within 6 months) becomes a 10 year old case tells you the efficacy of the system. The reality is far more worse than is shared or known. Just a few months ago, GOI shared some data on Sexual Harassment in 2018-19. And this is after constant pressurizing by Activists that GOI doesn t like. In fact, in 2021, Unicef had shared data about how India was one of the five countries where child brides are still prevalent. India denied but didn t produce any alternative data. The firing of Mr. James over NHFS data sets doesn t give it any brownie points to the present Government. What has happened in the last few years is that the Government for reasons of its own had been scrubbing and censoring a lot of data. I won t go far, just 2 day old story which I had shared just couple of days back. Roughly a 25 year old RPF constable kills his superior and kills 3 Muslims after going to various coaches and then the Government uses the defence of temporary insanity.

Even the mental instability defence has twists and turns

Incidentally, Press Trust of India is s private organization and not the public broadcaster of the old. And incidentally, just a few days back, it came to light that they hadn t paid Income tax for last 2-3 years. Because of issues in reward money, the public came to know otherwise they wouldn t have known. Coming back to the topic itself, there was a video where you could hear and see the accused stating after killing the three Muslims that if you want to remain in India, then you have to vote for only Modi or Yogi, otherwise this will happen. That video was scrubbed both from Twitter as well as YouTube. All centralized platforms at the very least, whether it is Google (Youtube) or Twitter or Meta uses its own media ID. Meta s being most problematic but that probably being a discussion for another day. The same censorship tools are applied rigorously and lot of incidents are buried. Cases of girls being thrown in lakes just after lakes or low numbers of conviction in case of gang rapes are more often than not disappears.

The above article shared just a few days ago that how low the conviction rates of gang rapes are in Gujarat tells you the story. You might get the story today, but wait for a few weeks and you will find that the story has disappeared. What most people do not know or understand is that the web is increasingly a public repository of idea, imaginations and trust and authoritarian regimes like Government of India is increasingly using both official as well as unofficial methods to suppress the same. To see that in the last 9 odd years, GOI has made the highest number of takedown requests and been either number one or number two tells all. My question is where we do from here ??? If even the Minister and her Ministry can do only whataboutery rather than answer the questions, then how we are supposed to come up solutions. And even if a solution exists, without the state and Center agreeing and co-operating with civil society, any solution will be far off the desired result. I am sorry that I at least have no answers

There are a lot of people talking about the Russian invasion of Ukraine and a lot of moving goalposts in such discussions. I think that everyone who wants to advocate for it should publish what they expect to happen and what specific things they consider as victory conditions. When Russia first invaded I thought they would win in a matter of weeks. I underestimated the determination of the Ukrainian people and the corruption and the incompetence and corruption of the Russian military. The first time I thought that Ukraine could win was when I read an analysis of the tires on Russian military vehicles breaking because of the cheapest available tires being bought and then not stored correctly to avoid damage, which led to the long stalled convoy. A successful military campaign requires many more difficult tasks than buying good tires and maintaining them correctly. An army that is too corrupt to buy the bare minimum of usable equipment and too incompetent to adapt to failures is not going to do well. The Ukrainians have done very well with the equipment available, one example is their use of off the shelf drones for dropping grenades into armoured vehicles and for targeting artillery. While the Russians have responded by buying Iranian military drones because they lack the industrial capacity to make their own ones. From the time when the Russians first got bogged down the Ukrainians have been mostly retaking their territory slowly and steadily. The Russians started the invasion with a significant advantage in aircraft, armoured vehicles, artillery, and ammunition. This advantage has been significantly decreased due to losses of vehicles and artillery, high rates of ammunition use, and Ukrainian capture of Russian equipment. The Ukrainians are getting new vehicles, aircraft, artillery, and ammunition from western countries while sanctions are preventing Russians from importing or manufacturing much. Currently one important factor for Russia is the ability of their airforce to attack Ukrainian positions while out of range of Ukrainian air defence systems. The MANPAD systems are good for close support but not good for long range. A problem that the Russians will have in the long term is running out of spare parts and being unable to properly maintain aircraft. This will result in loss of aircraft due to accidents and the inability to repair aircraft that has even minor damage. Here are my specific predictions:

1. I predict that by the end of 2023 Russia will have a much smaller number of military aircraft through maintenance problems even if Ukraine doesn t get long-range SAM systems.
2. I predict that by mid 2024 Ukraine will have air superiority. They will destroy many Russian SAM systems and be able to bomb Russian targets with little risk.
3. I predict that Russia won t impose any significant new conscription programs on their population. Such programs are extremely unpopular and Russia doesn t have the industrial capacity to equip a larger army as they can t properly equip their current army.
4. Currently Ukraine is making slow but steady progress in retaking their territory in the East. I predict that before the end of 2023 they will have cut all supply lines to Crimea from the mainland by having artillery that can accurately cover all the distance to the coast of the Sea of Azov. I also predict that the bridge over the Kerch strait will be mostly unusable from now on (on average less than 1/3 the bridge capacity usable). As fast as the Russians can repair it the Ukrainians will bomb it again. At most they will have half of the road lanes available to cars and will be unable to transport any significant amount of military equipment.
5. Due to Russians lacking supplies I predict that Ukraine will recapture at least half the Crimean land area by the end of 2023.
6. The regions of Luhansk and Donetsk will be the most difficult to capture as they have been held the longest. I predict that the war will not end until Ukraine controls everything within their 2013 borders including Luhansk and Donetsk. The final victory may happen due to the Russian military collapsing or due to a new Russian government ordering a withdrawal.
7. I predict that Russia will make significant efforts to help Trump get elected in 2024. But even if they succeed it will be too late for him to help them much or change the outcome.
8. I predict that Ukraine will win this war before the end of 2025. Even if some of my other predictions turn out to be incorrect I predict that by the end of 2025 the military forces of Russia and Ukraine will not be fighting and that it will be because Ukraine has given the Russian military a proper spanking. If something like the Troubles in Ireland happens (which is a real possibility) that doesn t count as a war.
9. I predict that Ukraine will not deploy any significant attack inside Russian territory. They will launch small scale attacks on specific military targets but do nothing that the Russian population might consider to be full scale war.
10. I predict that Putin will not lead Russia 2 months after Ukraine recaptures all their territory. He may not live for long after Ukraine wins, or the Russian withdrawal might happen because Putin dies of apparently natural causes.
11. After the war I predict that Ukraine will control all their territory from 2013 and there will be a demilitarised zone or no-fly zone in Russian territory.
12. I predict that after the war some parts of the Russian Federation will break free. There are many different groups who would like to be free of Russia and Ukraine destroying most of the Russian military will make things easy for them. A Russian civil war is a possibility.
13. I predict that the US will give minimal support to Russia after the war as a strategic plan to block China. I predict that the quality and efficacy of such support will be comparable to the US actions in the Middle East.

I welcome comments disagreeing with this. But please make specific predictions that can be tested and sign your name to them. If you don t think that a certain event will happen when I predict it then provide a date when you think it will happen or a date by which the opposite will have happened. Also please show enough confidence to make multiple predictions. I ve made 12 specific predictions, if you think I m doing badly then make at least 3 specific competing predictions. If you think that Russia will win then define what a win means in terms of territory occupied when fighting between armies ends and when that will happen. Also if you think that Russia will win then please make a prediction about whether there will be a Ukrainian equivalent of the IRA and if so what they will do.

co2mon.nz currently uses monitors based on Oliver Seiler s open source design which I am personally building. This post describes my exploration of how to achieve production of a CO2 monitor that could enable the growth of co2mon.nz.

Goals Primarily I want to design a CO2 monitor which allows the majority of the production process to be outsourced. In particular, the PCB should be able to be assembled in an automated fashion (PCBA). As a secondary goal, I d like to improve the aesthetics of the monitor while retaining the unique feature of displaying clear visual indication of the current ventilation level through coloured lights. Overall, I ll consider the project successfull if I can achieve a visually attractive CO2 monitor which takes me less than 10 minutes per monitor to assemble/box/ship and whose production cost has the potential to be lower than the current model.

PCB

Schematic The existing CO2 monitor design provides a solid foundation but relies upon the ESP32 Devkit board, which is intended for evaluation purposes and is not well suited to automated assembly. Replacing this devkit board with the underlying ESP32 module is the major change needed to enable PCBA production, which then also requires moving the supporting electronics from the devkit board directly onto the primary PCB. The basic ESP32 chipset used in the devkit boards is no longer available as a discrete module suitable for placement directly onto a PCB which means the board will also have to be updated to use a more modern variant of the ESP32 chipset which is in active production such as the ESP32-S3. The ESP32-S3-WROOM1-N4 module is a very close match to the original devkit and will be suitable for this project. In addition to the change of ESP module, I made the following other changes to the components in use:

• Added an additional temperature/humidity sensor (SHT30). The current monitors take temperature/humidity measurements from the SCD40 chipset. These are primarily intended to help in the calculation of CO2 levels and rely on an offset being subtracted to account for the heat generated by the electronic components themselves. I ve found their accuracy to OK, but not perfect. SHT30 is a cheap part, so its addition to hopefully provide improved temperature/humidity measurement is an easy choice.
• Swapped to USB-C instead of USB-B for the power connector. USB-C is much more common than USB-B and is also smaller and not as tall off the board which provides more flexibility in the case design.

With major components selected the key task is to draw the schematic diagram describing how they electrically connect to each other, which includes all the supporting electronics (e.g. resistors, capacitors, etc) needed. I started out trying to use the EasyEDA/OSHWLab ecosystem thinking the tight integration with JLCPCB s assembly services would be a benefit, but the web interface was too clunky and limiting and I quickly got frustrated. KiCad proved to be a much more pleasant and capable tool for the job. The reference design in the ESP32 datasheet (p28) and USB-C power supply examples from blnlabs were particularly helpful alongside the KiCad documentation and the example of the existing monitor in completing this step (click the image to enlarge).

Layout The next step is to physically lay out where each component from the schematic will sit on the PCB itself. Obviously this requires first determining the overall size, shape and outline of the board and needs to occur in iteration with the intended design of the overall monitor, including the case, to ensure components like switches and USB sockets line up correctly. In addition to the requirements around the look and function of the case, the components themselves also have considerations that must be taken into account, including:

• For best WiFi reception, the ESP32 antenna should be at the top of the monitor and should not have PCB underneath it, or for a specified distance either side of it.
• The SHT30 temperature sensor should be as far from any heat generating components (e.g. the ESP32, BME680 and SCD40 modules) as possible and also considering that any generated heat will rise, as low on the monitor as possible.
• The sensors measuring the air (SCD40, BME680 and SHT30) must have good exposure to the air outside the case.

Taking all of these factors into account I ended up with a square PCB containing a cutout in the top right so that the ESP32 antenna can sit within the overall square outline while still meeting its design requirements. The SCD40 and BME680 sit in the top left corner, near the edges for good airflow and far away from the SHT30 temperature sensor in the bottom left corner. The LEDs I placed in a horizontal row across the center of the board, the LCD in the bottom right, a push button on the right-hand side and the USB-C socket in the center at the bottom. Once the components are placed, the next big task is to route the traces (aka wires) between the components on the board such that all the required electrical connections are made without any unintended connections (aka shorts) being created. This is a fun constraint solving/optimisation challenge and takes on an almost artistic aspect with other PCB designers often having strong opinions on which layout is best. The majority of the traces and routing for this board were able to be placed on the top layer of the PCB, but I also made use of the back layer for a few traces to help avoid conflicts and deal with places where different traces needed to cross each other. It s easy to see how this step would be much more challenging and time consuming on a larger and more complex PCB design. The final touches were to add some debugging breakouts for the serial and JTAG ports on the ESP32-S3 and a logo and various other helpful text on the silkscreen layer that will be printed on the PCB so it looks nice.

Production For assembly of the PCB, I went with JLCPCB based out of China. The trickiest part of the process was component selection and ensuring that the parts I had planned in the schematic were available. JLCPCB in conjunction with lcsc.com provides a basic and extended part library. If you use only basic parts you get quicker and cheaper assembly, while using extended parts bumps your order into a longer process with a small fee charged for each component on the board. Initially I spent a lot of time selecting components (particularly LEDs and switches) that were in the basic library before realising that the ESP32 modules are only available in the extended library! I think the lesson is that unless you re building the most trivial PCB with only passive components you will almost certainly end up in the advanced assembly process anyway, so trying to stay within the basic parts library is not worth the time. Unfortunately the SCD40 sensor, the most crucial part of the monitor, is not stocked at all by JLCPCB/LCSC! To work around this JLCPCB will maintain a personal component library for you when you ship components to them to for use in future orders. Given the extra logistical time and hassle of having to do this, combined with having a number of SCD40 components already on hand I decided to have the boards assembled without this component populated for the initial prototype run. This also had the benefit of lowering the risk if something went wrong as the cost of the SCD40 is greater than the cost of the PCB and all the other components combined! I found the kicad-jlcpcb-tools plugin for KiCad invaluable for keeping track of what part from lcsc.com I was planning to use for each component and generating the necessary output files for JLCPCB. The plugin allows you to store these mappings in your actual schematic which is very handy. The search interface it provides is fairly clunky and I found it was often easier to search for the part I needed on lcsc.com and then just copy the part number across into the plugin s search box rather than trying to search by name or component type. The LCD screen is the remaining component which is not easily assembled onto the PCB directly, but as you ll see next, this actually turned out to be OK as integrating the screen directly into the case makes the final assembly process smoother. The final surprise in the assembly process was the concept of edge rails, additional PCB material that is needed on either side of the board to help with feeding it through the assembly machine in the correct position. These can be added automatically by JLCPCB and have to be snapped off after the completed boards are received. I hadn t heard about these before and I was a little worried that they d interfere or get in the way of either the antenna cut-out at the top of the board, or the switch on the right hand side as it overhangs the edge so it can sit flush with the case. In the end there was no issue with the edge rails. The switch was placed hanging over them without issue and snapping them off once the boards arrived was a trivial 30s job using a vice to hold the edge rail and then gently tipping the board over until it snapped off - the interface between the board and the rails while solid looking has obviously been scored or perforated in some way during the production process so the edge breaks cleanly and smoothly. Magic! The process was amazingly quick with the completed PCBs (picture above) arriving within 7 days of the order being placed and looking amazing.

Case

Design I mocked up a very simple prototype of the case in FreeCAD during the PCB design process to help position and align the placement of the screen, switch and USB socket on the PCB as all three of these components interface directly with the edges of the case. Initially this design was similar to the current monitor design where the PCB (with lights and screen attached) sits in the bottom of the case, which has walls containing grilles for airflow and then a separate transparent perspex is screwed onto the top to complete the enclosure. As part of the aesthetic improvements for the new monitor I wanted to move away from a transparent front panel to something opaque but still translucent enough to allow the colour of the lights to show through. Without a transparent front panel the LCD also needs to be mounted directly into the case itself. The first few prototype iterations followed the design of the original CO2 monitor with a flat front panel that attaches to the rest of the case containing the PCB, but the new requirement to also attach the LCD to the front panel proved to make this unworkable. To stay in place the LCD has to be pushed onto mounting poles containing a catch mechanism which requires a moderate amount of force and applying that force to the LCD board when it is already connected to the PCB is essentially impossible. As a result I ended up completely flipping the design such that the front panel is a single piece of plastic that also encompasses the walls of the case and contains appropriate mounting stakes for both the screen and the main PCB. Getting to this design hugely simplified the assembly process. Starting with an empty case lying face down on a bench, the LCD screen is pushed onto the mounting poles and sits flush with the cover of the case - easily achieved without the main PCB yet in place. Next, the main PCB is gently lowered into the case facing downwards and sits on the mounting pole in each corner with the pins for the LCD just protruding through the appropriate holes in the PCB ready to be quickly soldered into place (this took significant iteration and tuning of dimensions/positioning to achieve!). Finally, a back panel can be attached which holds the PCB in place and uses cantilever snap joints to click on to the rest of the case. Overall the design is a huge improvement over the previous case which required screws and spacers to position the PCB and cover relative to the rest of the case, with the spacers and screws being particularly fiddly to work with. The major concern I had with the new design was that the mount to attach the monitor to the wall has moved from being attached to the main case and components directly to needing to be on the removable back panel - if the clips holding this panel to the case fail the core part of the monitor will fall off the wall which would not be good. To guard against this I ve doubled the size and number of clips at the top of the case (which bears the weight) and the result seems very robust in my testing. To completely assemble a monitor, including the soldering step takes me about 2-3 minutes individually, and would be even quicker if working in batches.

Production Given the number of design/testing iterations required to fine tune the case I chose not to outsource case production for now and used my 3D printer to produce them. I ve successfully used JLCPCB s 3D printing service for the previous case design, so I m confident that getting sufficient cases printed from JLCPCB or another supplier will not be an issue now that the design is finalised. I tried a variety of filament colours, but settled on a transparent filament which once combined in the necessary layers to form the case is not actually transparent like perspex is, but provides a nice translucent medium which achieves the goal of having the light colour visible without exposing all of the circuit board detail. There s room for future improvement in the positioning of the LEDs on the circuit board to provide a more even distribution of light across the case but overall I really like the way the completed monitor ends up looking.

Evaluation Building this monitor has been a really fun project, both in seeing something progress from an idea, to plans on a screen to a nice physical thing on my wall, but also in learning and developing a bunch of new skills in PCB design, assembly and 3D design. The goal of having a CO2 monitor which I can outsource the vast majority of production of is as close to being met as I think is possible without undertaking the final proof of placing a large order. I ve satisfied myself that each step is feasible and that the final assembly process is quick, easy and well below the level of effort and time it was taking me to produce the original monitors. Cost wise it s also a huge win, primarily in terms of the time taken, but also in the raw components - currently the five prototypes I ordered and built are on par with the component cost of the original CO2 monitor, but this will drop further with larger orders due to price breaks and amortisation of the setup and shipping expenses across more monitors. This project has also given me a much better appreciation for how much I m only just scratching the surface of the potential complexities and challenges in producing a hardware product of this type. I m reasonably confident I could successfully produce a few hundred and maybe even a few thousand monitors using this approach, but it s also clear that getting beyond that point is and would be a whole further level of effort and learning. Hardware is hard work. That s not news to anyone, including me, but there is something to be said for experiencing the process first hand to make the reality of what s required real. The PCB and case designs are both shared and can be found at https://github.com/co2monnz/co2monitor-pcb and https://github.com/co2monnz/cad, feedback and suggestions welcome!

After an upgrade of my PC's mainboard BIOS the boot would take a minute or more to complete and sometimes the lightdm login screen would sit there but not accept keyboard input for another minute or so. Then the keyboard got enabled and I could log in normally. Everything worked fine after that bootup struggle completed. This was fully reproducible and persisted across reboots. Weird. The kernel dmesg log showed entries that looked suspicious: Googleing these error -110 and error -71 is a bit hard. Now why the USB driver does not give useful error messages instead of archaic errno-style numbers escapes me. This is not the 80s anymore. The wisdom of the crowd says error -110 is something around "the USB port power supply was exceeded" [source]. Now lsusb -tv shows device 1-7 ... to be my USB keyboard. I somehow doubt that wants more power than the hub is willing to provide. The Archlinux BBS Forums recommend to piece together information from drivers/usb/host/ohci.h and (updated from their piece which is from 2012) /tools/include/uapi/asm-generic/errno.h. This is why some people then consider -110 to mean "Connection timed out". Nah, not likely either. Reading through the kernel source around drivers/usb/host did not enlighten me either. To the contrary. Uuugly. There seems to be no comprehensive list what these error codes mean. And the numbers are assigned to errors conditions quite arbitrarily. And - of course - there is no documentation. "It was hard to do, so it should be hard to understand as well." Luckily some of the random musings I read through contained some curious advice: power cycle the host. So I did and that did not make the error go away. Other people insisted on removing cables out of wall sockets, unplugging everything and conducting esoteric rituals. That made it dawn on me, the mainboard of course nicely powers the USB in "off" state, too. So switching the power supply off (yes, these have a separate switch, go find yours), waiting a bit for capacitors to drain and switching things back on and ... the errors were gone, the system booted within seconds again. So the takeaway message: If you get random error messages like on devices that previously worked fine ... completely remove power from the host, the hubs and the USB devices. So they forget they saw each other on the bus before. And when they see each other after that blackout, they will happily go through negotiating protocol details with each other again successfully.

EDIT: One of my 2 keys has died. There are what seems like golden bubbles under the epoxy, over one of the chips and those were not there before. I've emailed SoloKeys and I'm waiting for a reply, but for now, I've stopped using the Solo V2 altogether :( I recently received the two Solo V2 hardware tokens I ordered as part of their crowdfunding campaign, back in March 2022. It did take them longer than advertised to ship me the tokens, but that's hardly unexpected from such small-scale, crowdfunded undertaking. I'm mostly happy about my purchase and I'm glad to get rid of the aging Tomu boards I was using as U2F tokens¹. Still, beware: I am not sure it's a product I would recommend if what you want is simply something that works. If you do not care about open-source hardware, the Solo V2 is not for you. The Good I first want to mention I find the Solo V2 gorgeous. I really like the black and gold color scheme of the USB-A model (which is reversible!) and it seems like a well built and solid device. I'm not afraid to have it on my keyring and I fully expect it to last a long time. I'm also very impressed by the modular design: the PCB sits inside a shell, which decouples the logic from the USB interface and lets them manufacture a single board for both the USB-C and USB-A models. The clear epoxy layer on top of the PCB module also looks very nice in my opinion. I'm also very happy the Solo V2 has capacitive touch buttons instead of physical "clicky" buttons, as it means the device has no moving parts. The token has three buttons (the gold metal strips): one on each side of the device and a third one near the keyhole. As far as I've seen, the FIDO2 functions seem to work well via the USB interface and do not require any configuration on a Debian 12 machine. I've already migrated to the Solo V2 for web-based 2FA and I am in the process of migrating to an SSH ed25519-sk key. Here is a guide I recommend if you plan on setting those up with a Solo V2. The Bad and the Ugly Sadly, the Solo V2 is far from being a perfect project. First of all, since the crowdfunding campaign is still being fulfilled, it is not currently commercially available. Chances are you won't be able to buy one directly before at least Q4 2023. I've also hit what seems to be a pretty big firmware bug, or at least, one that affects my use case quite a bit. Invoking gpg crashes the Solo V2 completely if you also have scdaemon installed. Since scdaemon is necessary to use gpg with an OpenPGP smartcard, this means you cannot issue any gpg commands (like signing a git commit...) while the Solo V2 is plugged in. Any gpg commands that queries scdaemon, such as gpg --edit-card or gpg --sign foo.txt times out after about 20 seconds and leaves the token unresponsive to both touch and CLI commands. The way to "fix" this issue is to make sure scdaemon does not interact with the Solo V2 anymore, using the reader-port argument:

1. Plug both your Solo V2 and your OpenPGP smartcard
2. To get a list of the tokens scdaemon sees, run the following command: $ echo scd getinfo reader_list gpg-connect-agent --decode awk '/^D/ print $2 '
3. Identify your OpenPGP smartcard. For example, my Nitrokey Start is listed as 20A0:4211:FSIJ-1.2.15-43211613:0
4. Create a file in ~/.gnupg/scdaemon.conf with the following line reader-port $YOUR_TOKEN_ID. For example, in my case I have: reader-port 20A0:4211:FSIJ-1.2.15-43211613:0
5. Reload scdaemon: $ gpgconf --reload scdaemon

Although this is clearly a firmware bug², I do believe GnuPG is also partly to blame here. Let's just say I was not very surprised to have to battle scdaemon again, as I've had previous issues with it. Which leads me to my biggest gripe so far: it seems SoloKeys (the company) isn't really fixing firmware issues anymore and doesn't seems to care. The last firmware release is about a year old. Although people are experiencing serious bugs, there is no official way to report them, which leads to issues being seemingly ignored. For example, the NFC feature is apparently killing keys (!!!), but no one from the company seems to have acknowledged the issue. The same goes for my GnuPG bug, which was flagged in September 2022. For a project that mainly differentiates itself from its (superior) competition by being "Open", it's not a very good look... Although SoloKeys is still an unprofitable open source side business of its creators ³, this kind of attitude certainly doesn't help foster trust. Conclusion If you want to have a nice, durable FIDO2 token, I would suggest you get one of the many models Yubico offers. They are similarly priced, are readily commercially available, are part of a nice and maintained software ecosystem and have more features than the Solo V2 (OpenPGP support being the one I miss the most). Yubikeys are the practical option. What they are not is open-source hardware, whereas the Solo V2 is. As bunnie very well explained on his blog in 2019, it does not mean the later is inherently more trustable than the former, but it does make the Solo V2 the ideological option. Knowledge is power and it should be free. As such, tread carefully with SoloKeys, but don't dismiss them altogether: the Solo V2 is certainly functioning well enough for me.

For DebConf23, we're pleased to announce opening of registration and call for proposal. Following is the info text -

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Registration and the Call for Proposals for DebConf23 are now open. The 24th edition of the Debian annual conference will be held from September 10th to September 17th, 2023, in Infopark, Kochi, India. The main conference will be preceded by DebCamp, which will take place from September 3rd to September 9th, 2023. The registration form can be accessed by creating an account on the DebConf23 website and clicking on "register" in the profile section. The number of attendees is capped at 300 this year. All registrations will be reviewed by bursary team, and completing the registration form does not guarantee attendance. As always, basic registration for DebConf is free of charge for attendees. If you are attending the conference in a professional capacity or as a representative of your company, we kindly ask that you consider registering in one of our paid categories to help cover the costs of organizing the conference and to support subsidizing other community members. The last day to register with guaranteed swag is 5th August. We also encourage eligible individuals to apply for a diversity bursary. Travel, food, and accommodation bursaries are available. More details can be found on the bursary info page. The last day to apply for a bursary is 1st July. Applicants should receive feedback on their bursary application by 16th July. The call for proposals for talks, discussions and other activities is also open. To submit a proposal you need to create an account on the website, and then use the "Submit Talk" button in the profile section. The last day to submit and have your proposal be considered for the main conference schedule, with video coverage guaranteed, is 13th August. DebConf23 is also accepting sponsors. Interested companies and organizations may contact the DebConf team through sponsors@debconf.org or visit the DebConf23 website.

Review: Night Watch, by Terry Pratchett

Series:	Discworld #29
Publisher:	Harper
Copyright:	November 2002
Printing:	August 2014
ISBN:	0-06-230740-1
Format:	Mass market
Pages:	451

Night Watch is the 29th Discworld novel and the sixth Watch novel. I would really like to tell people they could start here if they wanted to, for reasons that I will get into in a moment, but I think I would be doing you a disservice. The emotional heft added by having read the previous Watch novels and followed Vimes's character evolution is significant. It's the 25th of May. Vimes is about to become a father. He and several of the other members of the Watch are wearing sprigs of lilac for reasons that Sergeant Colon is quite vehemently uninterested in explaining. A serial killer named Carcer the Watch has been after for weeks has just murdered an off-duty sergeant. It's a tense and awkward sort of day and Vimes is feeling weird and wistful, remembering the days when he was a copper and not a manager who has to dress up in ceremonial armor and meet with committees. That may be part of why, when the message comes over the clacks that the Watch have Carcer cornered on the roof of the New Hall of the Unseen University, Vimes responds in person. He's grappling with Carcer on the roof of the University Library in the middle of a magical storm when lightning strikes. When he wakes up, he's in the past, shortly after he joined the Watch and shortly before the events of the 25th of May that the older Watch members so vividly remember and don't talk about. I have been saying recently in Discworld reviews that it felt like Pratchett was on the verge of a breakout book that's head and shoulders above Discworld prior to that point. This is it. This is that book. The setup here is masterful: the sprigs of lilac that slowly tell the reader something is going on, the refusal of any of the older Watch members to talk about it, the scene in the graveyard to establish the stakes, the disconcerting fact that Vetinari is wearing a sprig of lilac as well, and the feeling of building tension that matches the growing electrical storm. And Pratchett never gives into the temptation to explain everything and tip his hand prematurely. We know the 25th is coming and something is going to happen, and the reader can put together hints from Vimes's thoughts, but Pratchett lets us guess and sometimes be right and sometimes be wrong. Vimes is trying to change history, which adds another layer of uncertainty and enjoyment as the reader tries to piece together both the true history and the changes. This is a masterful job at a "what if?" story. And, beneath that, the commentary on policing and government and ethics is astonishingly good. In a review of an earlier Watch novel, I compared Pratchett to Dickens in the way that he focuses on a sort of common-sense morality rather than political theory. That is true here too, but oh that moral analysis is sharp enough to slide into you like a knife. This is not the Vimes that we first met in Guards! Guards!. He has has turned his cynical stubbornness into a working theory of policing, and it's subtle and complicated and full of nuance that he only barely knows how to explain. But he knows how to show it to people.

Keep the peace. That was the thing. People often failed to understand what that meant. You'd go to some life-threatening disturbance like a couple of neighbors scrapping in the street over who owned the hedge between their properties, and they'd both be bursting with aggrieved self-righteousness, both yelling, their wives would either be having a private scrap on the side or would have adjourned to a kitchen for a shared pot of tea and a chat, and they all expected you to sort it out. And they could never understand that it wasn't your job. Sorting it out was a job for a good surveyor and a couple of lawyers, maybe. Your job was to quell the impulse to bang their stupid fat heads together, to ignore the affronted speeches of dodgy self-justification, to get them to stop shouting and to get them off the street. Once that had been achieved, your job was over. You weren't some walking god, dispensing finely tuned natural justice. Your job was simply to bring back peace.

When Vimes is thrown back in time, he has to pick up the role of his own mentor, the person who taught him what policing should be like. His younger self is right there, watching everything he does, and he's desperately afraid he'll screw it up and set a worse example. Make history worse when he's trying to make it better. It's a beautifully well-done bit of tension that uses time travel as the hook to show both how difficult mentorship is and also how irritating one's earlier naive self would be.

He wondered if it was at all possible to give this idiot some lessons in basic politics. That was always the dream, wasn't it? "I wish I'd known then what I know now"? But when you got older you found out that you now wasn't you then. You then was a twerp. You then was what you had to be to start out on the rocky road of becoming you now, and one of the rocky patches on that road was being a twerp.

The backdrop of this story, as advertised by the map at the front of the book, is a revolution of sorts. And the revolution does matter, but not in the obvious way. It creates space and circumstance for some other things to happen that are all about the abuse of policing as a tool of politics rather than Vimes's principle of keeping the peace. I mentioned when reviewing Men at Arms that it was an awkward book to read in the United States in 2020. This book tackles the ethics of policing head-on, in exactly the way that book didn't. It's also a marvelous bit of competence porn. Somehow over the years, Vimes has become extremely good at what he does, and not just in the obvious cop-walking-a-beat sort of ways. He's become a leader. It's not something he thinks about, even when thrown back in time, but it's something Pratchett can show the reader directly, and have the other characters in the book comment on. There is so much more that I'd like to say, but so much would be spoilers, and I think Night Watch is more effective when you have the suspense of slowly puzzling out what's going to happen. Pratchett's pacing is exquisite. It's also one of the rare Discworld novels where Pratchett fully commits to a point of view and lets Vimes tell the story. There are a few interludes with other people, but the only other significant protagonist is, quite fittingly, Vetinari. I won't say anything more about that except to note that the relationship between Vimes and Vetinari is one of the best bits of fascinating subtlety in all of Discworld. I think it's also telling that nothing about Night Watch reads as parody. Sure, there is a nod to Back to the Future in the lightning storm, and it's impossible to write a book about police and street revolutions without making the reader think about Les Miserables, but nothing about this plot matches either of those stories. This is Pratchett telling his own story in his own world, unapologetically, and without trying to wedge it into parody shape, and it is so much the better book for it. The one quibble I have with the book is that the bits with the Time Monks don't really work. Lu-Tze is annoying and flippant given the emotional stakes of this story, the interludes with him are frustrating and out of step with the rest of the book, and the time travel hand-waving doesn't add much. I see structurally why Pratchett put this in: it gives Vimes (and the reader) a time frame and a deadline, it establishes some of the ground rules and stakes, and it provides a couple of important opportunities for exposition so that the reader doesn't get lost. But it's not good story. The rest of the book is so amazingly good, though, that it doesn't matter (and the framing stories for "what if?" explorations almost never make much sense). The other thing I have a bit of a quibble with is outside the book. Night Watch, as you may have guessed by now, is the origin of the May 25th Pratchett memes that you will be familiar with if you've spent much time around SFF fandom. But this book is dramatically different from what I was expecting based on the memes. You will, for example see a lot of people posting "Truth, Justice, Freedom, Reasonably Priced Love, And a Hard-Boiled Egg!", and before reading the book it sounds like a Pratchett-style humorous revolutionary slogan. And I guess it is, sort of, but, well... I have to quote the scene:

"You'd like Freedom, Truth, and Justice, wouldn't you, Comrade Sergeant?" said Reg encouragingly. "I'd like a hard-boiled egg," said Vimes, shaking the match out. There was some nervous laughter, but Reg looked offended. "In the circumstances, Sergeant, I think we should set our sights a little higher " "Well, yes, we could," said Vimes, coming down the steps. He glanced at the sheets of papers in front of Reg. The man cared. He really did. And he was serious. He really was. "But...well, Reg, tomorrow the sun will come up again, and I'm pretty sure that whatever happens we won't have found Freedom, and there won't be a whole lot of Justice, and I'm damn sure we won't have found Truth. But it's just possible that I might get a hard-boiled egg."

I think I'm feeling defensive of the heart of this book because it's such an emotional gut punch and says such complicated and nuanced things about politics and ethics (and such deeply cynical things about revolution). But I think if I were to try to represent this story in a meme, it would be the "angels rise up" song, with all the layers of meaning that it gains in this story. I'm still at the point where the lilac sprigs remind me of Sergeant Colon becoming quietly furious at the overstep of someone who wasn't there. There's one other thing I want to say about that scene: I'm not naturally on Vimes's side of this argument. I think it's important to note that Vimes's attitude throughout this book is profoundly, deeply conservative. The hard-boiled egg captures that perfectly: it's a bit of physical comfort, something you can buy or make, something that's part of the day-to-day wheels of the city that Vimes talks about elsewhere in Night Watch. It's a rejection of revolution, something that Vimes does elsewhere far more explicitly. Vimes is a cop. He is in some profound sense a defender of the status quo. He doesn't believe things are going to fundamentally change, and it's not clear he would want them to if they did. And yet. And yet, this is where Pratchett's Dickensian morality comes out. Vimes is a conservative at heart. He's grumpy and cynical and jaded and he doesn't like change. But if you put him in a situation where people are being hurt, he will break every rule and twist every principle to stop it.

He wanted to go home. He wanted it so much that he trembled at the thought. But if the price of that was selling good men to the night, if the price was filling those graves, if the price was not fighting with every trick he knew... then it was too high. It wasn't a decision that he was making, he knew. It was happening far below the areas of the brain that made decisions. It was something built in. There was no universe, anywhere, where a Sam Vimes would give in on this, because if he did then he wouldn't be Sam Vimes any more.

This is truly exceptional stuff. It is the best Discworld novel I have read, by far. I feel like this was the Watch novel that Pratchett was always trying to write, and he had to write five other novels first to figure out how to write it. And maybe to prepare Discworld readers to read it. There are a lot of Discworld novels that are great on their own merits, but also it is 100% worth reading all the Watch novels just so that you can read this book. Followed in publication order by The Wee Free Men and later, thematically, by Thud!. Rating: 10 out of 10

I have several TB worth of family photos, videos, and other data. This needs to be backed up and archived. Backups and archives are often thought of as similar. And indeed, they may be done with the same tools at the same time. But the goals differ somewhat: Backups are designed to recover from a disaster that you can fairly rapidly detect. Archives are designed to survive for many years, protecting against disaster not only impacting the original equipment but also the original person that created them. Reflecting on this, it implies that while a nice ZFS snapshot-based scheme that supports twice-hourly backups may be fantastic for that purpose, if you think about things like family members being able to access it if you are incapacitated, or accessibility in a few decades time, it becomes much less appealing for archives. ZFS doesn t have the wide software support that NTFS, FAT, UDF, ISO-9660, etc. do. This post isn t about the pros and cons of the different storage media, nor is it about the pros and cons of cloud storage for archiving; these conversations can readily be found elsewhere. Let s assume, for the point of conversation, that we are considering BD-R optical discs as well as external HDDs, both of which are too small to hold the entire backup set. What would you use for archiving in these circumstances? Establishing goals The goals I have are:

• Archives can be restored using Linux or Windows (even though I don t use Windows, this requirement will ensure the broadest compatibility in the future)
• The archival system must be able to accommodate periodic updates consisting of new files, deleted files, moved files, and modified files, without requiring a rewrite of the entire archive dataset
• Archives can ideally be mounted on any common OS and the component files directly copied off
• Redundancy must be possible. In the worst case, one could manually copy one drive/disc to another. Ideally, the archiving system would automatically track making n copies of data.
• While a full restore may be a goal, simply finding one file or one directory may also be a goal. Ideally, an archiving system would be able to quickly tell me which discs/drives contain a given file.
• Ideally, preserves as much POSIX metadata as possible (hard links, symlinks, modification date, permissions, etc). However, for the archiving case, this is less important than for the backup case, with the possible exception of modification date.
• Must be easy enough to do, and sufficiently automatable, to allow frequent updates without error-prone or time-consuming manual hassle

I would welcome your ideas for what to use. Below, I ll highlight different approaches I ve looked into and how they stack up. Basic copies of directories The initial approach might be one of simply copying directories across. This would work well if the data set to be archived is smaller than the archival media. In that case, you could just burn or rsync a new copy with every update and be done. Unfortunately, this is much less convenient with data of the size I m dealing with. rsync is unavailable in that case. With some datasets, you could manually design some rsyncs to store individual directories on individual devices, but that gets unwieldy fast and isn t scalable. You could use something like my datapacker program to split the data across multiple discs/drives efficiently. However, updates will be a problem; you d have to re-burn the entire set to get a consistent copy, or rely on external tools like mtree to reflect deletions. Not very convenient in any case. So I won t be using this. tar or zip While you can split tar and zip files across multiple media, they have a lot of issues. GNU tar s incremental mode is clunky and buggy; zip is even worse. tar files can t be read randomly, making it extremely time-consuming to extract just certain files out of a tar file. The only thing going for these formats (and especially zip) is the wide compatibility for restoration. dar Here we start to get into the more interesting tools. Dar is, in my opinion, one of the best Linux tools that few people know about. Since I first wrote about dar in 2008, it s added some interesting new features; among them, binary deltas and cloud storage support. So, dar has quite a few interesting features that I make use of in other ways, and could also be quite helpful here:

• Dar can both read and write files sequentially (streaming, like tar), or with random-access (quick seek to extract a subset without having to read the entire archive)
• Dar can apply compression to individual files, rather than to the archive as a whole, faciliting both random access and resilience (corruption in one file doesn t invalidate all subsequent files). Dar also supports numerous compression algorithms including gzip, bzip2, xz, lzo, etc., and can omit compressing already-compressed files.
• The end of each dar file contains a central directory (dar calls this a catalog). The catalog contains everything necessary to extract individual files from the archive quickly, as well as everything necessary to make a future incremental archive based on this one. Additionally, dar can make and work with isolated catalogs a file containing the catalog only, without data.
• Dar can split the archive into multiple pieces called slices. This can best be done with fixed-size slices ( slice and first-slice options), which let the catalog regord the slice number and preserves random access capabilities. With the execute option, dar can easily wait for a given slice to be burned, etc.
• Dar normally stores an entire new copy of a modified file, but can optionally store an rdiff binary delta instead. This has the potential to be far smaller (think of a case of modifying metadata for a photo, for instance).

Additionally, dar comes with a dar_manager program. dar_manager makes a database out of dar catalogs (or archives). This can then be used to identify the precise archive containing a particular version of a particular file. All this combines to make a useful system for archiving. Isolated catalogs are tiny, and it would be easy enough to include the isolated catalogs for the entire set of archives that came before (or even the dar_manager database file) with each new incremental archive. This would make restoration of a particular subset easy. The main thing to address with dar is that you do need dar to extract the archive. Every dar release comes with source code and a win64 build. dar also supports building a statically-linked Linux binary. It would therefore be easy to include win64 binary, Linux binary, and source with every archive run. dar is also a part of multiple Linux and BSD distributions, which are archived around the Internet. I think this provides a reasonable future-proofing to make sure dar archives will still be readable in the future. The other challenge is user ability. While dar is highly portable, it is fundamentally a CLI tool and will require CLI abilities on the part of users. I suspect, though, that I could write up a few pages of instructions to include and make that a reasonably easy process. Not everyone can use a CLI, but I would expect a person that could follow those instructions could be readily-enough found. One other benefit of dar is that it could easily be used with tapes. The LTO series is liked by various hobbyists, though it could pose formidable obstacles to non-hobbyists trying to aceess data in future decades. Additionally, since the archive is a big file, it lends itself to working with par2 to provide redundancy for certain amounts of data corruption. git-annex git-annex is an interesting program that is designed to facilitate managing large sets of data and moving it between repositories. git-annex has particular support for offline archive drives and tracks which drives contain which files. The idea would be to store the data to be archived in a git-annex repository. Then git-annex commands could generate filesystem trees on the external drives (or trees to br burned to read-only media). In a post about using git-annex for blu-ray backups, an earlier thread about DVD-Rs was mentioned. This has a few interesting properties. For one, with due care, the files can be stored on archival media as regular files. There are some different options for how to generate the archives; some of them would place the entire git-annex metadata on each drive/disc. With that arrangement, one could access the individual files without git-annex. With git-annex, one could reconstruct the final (or any intermediate) state of the archive appropriately, handling deltions, renames, etc. You would also easily be able to know where copies of your files are. The practice is somewhat more challenging. Hundreds of thousands of files what I would consider a medium-sized archive can pose some challenges, running into hours-long execution if used in conjunction with the directory special remote (but only minutes-long with a standard git-annex repo). Ruling out the directory special remote, I had thought I could maybe just work with my files in git-annex directly. However, I ran into some challenges with that approach as well. I am uncomfortable with git-annex mucking about with hard links in my source data. While it does try to preserve timestamps in the source data, these are lost on the clones. I wrote up my best effort to work around all this. In a forum post, the author of git-annex comments that I don t think that CDs/DVDs are a particularly good fit for git-annex, but it seems a couple of users have gotten something working. The page he references is Managing a large number of files archived on many pieces of read-only medium. Some of that discussion is a bit dated (for instance, the directory special remote has the importtree feature that implements what was being asked for there), but has some interesting tips. git-annex supplies win64 binaries, and git-annex is included with many distributions as well. So it should be nearly as accessible as dar in the future. Since git-annex would be required to restore a consistent recovery image, similar caveats as with dar apply; CLI experience would be needed, along with some written instructions. Bacula and BareOS Although primarily tape-based archivers, these do also also nominally support drives and optical media. However, they are much more tailored as backup tools, especially with the ability to pull from multiple machines. They require a database and extensive configuration, making them a poor fit for both the creation and future extractability of this project. Conclusions I m going to spend some more time with dar and git-annex, testing them out, and hope to write some future posts about my experiences.