So, depending on who you talk to, we've got about 9 weeks to go, or maybe 8 weeks. It all depends on whether we can have our way and have a caesarean on the 8th of October. Of course, the baby may have other thoughts on the matter as well... We've had our last planned house guest until Sarah's Mum and Aunty arrive, so we've put the mattress in storage and donated the bed frame to Goodwill. We've acquired a crib (I keep wanting to call it a cot) and a changing table/chest of drawers and put them in place in the baby's room. Last night we bought a car seat. I think the only major item left to get is a stroller. Sarah's pregnancy is still going well. The baby's still extremely active, and has had the hiccups quite a few times in the last week. Apparently that's him trying to breathe. I'm somewhat surprised they don't drown in there trying to do that... Speaking of breathing, our overly cautious obstetrician wanted Sarah to have two shots of steroids, to aid in the baby's lung development "just in case" he was born (or had to be delivered) very early. We felt it was somewhat unnecessary, but thought we'd be kicking ourselves if something happened and we didn't do it. There didn't seem to be any outrageous adverse effects from doing so, so we went along with it. Twice in a week (the second time today) Sarah's had blurry vision followed by a headache, so she called up the hospital today when it happened, and they told her to come in and get checked out. We spent about 4 hours in labor and delivery this afternoon. It turns out the reason they wanted us to come in was because the symptoms could be a sign of preeclampsia. The tests proved otherwise, and they couldn't really offer an explanation for what was going on other than migraines, so they eventually sent us home again. It was nice to get a preview of hospital's labor and delivery ward.

A friend recently asked for advice on a “REALLY small laptop/word processor thingy that would pretty much fit into a (big) pocket, and that only needs to write/word process“. The first problem here is that most people associate “word processing” with desktop publishing and document management. Programs such as MS-Word are considered as having the features required of a word-processor (which includes spelling and grammer checking/correcting, annotations, colours, etc). Programs that have all those features take a lot of CPU power. A Pentium-4 system might be considered the minimum requirement for running a recent version of MS-Word. But a hand-held device can’t have such a powerful CPU (it’s too small to be able to dissipate the heat from such a CPU or contain batteries that can produce enough power to tun it). The next problem is the issue of screen space. A VGA resolution screen (640×480) is regarded as high resolution in the PDA market. Such a resolution does not work with a word-processor that has three toolbars at the top of it’s screen and a paperclip taking up space at the bottom right! I’m sure that everyone who was using computers in the early 1990’s can recall the minimal word-processing programs. One thing to consider is that 640×480 in a 15 inch CRT screen is much more useful than 640×480 in a hand-held device as the larger screen can have fewer pixels per character and therefore display more text on the screen. An added complication is that there are two methods of input for PDAs. One is to have a hardware keyboard (which may be a separate device or may be part of the PDA) and the other is to have a keyboard displayed on the screen. A hardware keyboard makes the device larger and a software keyboard takes up precious screen space (you just can’t win). My PDA is an iPaQ model h3900. It has 64M of RAM, 32M of flash, no hardware keyboard, and a screen resolution of 320×240. I have done some serious writing on my iPaQ (including writing an entire article for Linux Journal) and it works reasonably well. For serious writing you can produce plain text on a PDA and then easily paste it into your program of choice on a PC later (PDAs generally support connection to a PC via serial port and/or USB). The challenge is editing files that originate on a PC using a PDA. Generally I try and use HTML and TeX for my formatted documents so the text versions of those formats are easy to edit once you have learned them. Taking data from a MD-Word file, editing it on a PDA, and then taking it back to the PC would cause many problems and probably wouldn’t be worth attempting. Recently I have been using my iPaQ for writing notes about email and blog posts that I will write. If I get an idea then I immediately write some notes about it on my iPaQ and then usually type it again instead of downloading it. For example the notes for this post were “write about RAM, storage, and screen resolution”. Often getting the initial ideas to start writing is the hard part. Writing a 500 to 1000 word blog post or message is easy once I have the ideas. If I was going to buy a new PDA now I would prefer one with a hardware keyboard, the loss of screen space for a keyboard on the touch-screen is a serious impediment to writing. The maximum amount of text that can be displayed on the screen at any one time limits the complexity of what I work on (see my post about monitors for developers). Another factor is the fact that for small notes the amount of time taken to remove the stylus from it’s bay is greater than the amount of time saved by using it. So I end up writing small notes using my finger-nail on the touch-screen which is significantly slower than using a keyboard (even the crummy ones that PDAs have). Of course the keyboard would still have to be QWERTY and have raised keys so that I can touch-type. I haven’t investigated this seriously as my iPaQ is good enough to last me for another year or two at least and I’ve got an unused spare iPaQ to replace it when it fails. But if anyone has any recommendations of Linux based PDAs with keyboards then I would appreciate some comments.

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Last thursday and friday, I spent around eleven hours in the InterCity Express (ICE) of Deutsche Bahn. I was online, using Simyo GPRS, during this entire time. Thanks to the cellular network repeaters in ICE’s coach 3 and 23, this has worked reasonably well and has cost me EUR 5,27 - in a tariff with no basic charge and no commitment. I really like that, because this usage of the mobile cellular network would have cost about fifty times more just a year ago. Thanks, Simyo, E Plus and the other E Plus resellers who have made the first step to reducing the cost of mobile Internet in Germany. A few technical notes:

• The repeaters in the ICE coaches do only repeat GSM and thus GPRS, but not UMTS. It is advised to lock the UMTS card to GPRS when using Internet from inside the ICE, since the card will otherwise move back and forth between UMTS and GPRS millions of times, which will always result in more than just a few seconds outage. It is much better to live with GPRS’ abysmally large latency.
• I took the opportunity to empty my still-active, old, GPRS only, Simyo SIM which still holds like fifteen Euros. I suspect that I’ll need two more trips of this magnitude to successfully get rid of the amount on that prepaid card.
• I need an external antenna for my UMTS card - it worked really really bad in my mom’s apartment right in the middle of Hamburg.
• There seem to be a number of independent issues in Debian sid (the reason why I am blogging this in English): The connection occasionally hangs (a couple of times an hour) and does not come back by itself. Often, poff/pon is enough, but sometimes it is necessary to pull the UMTS card (an Option 3G PC-Card Datacard) and to re-insert it since there was no answer any more on ttyUSB0. Very annoying.
• The Option 3G Datacard behaves differently depending on the SIM that is inserted. With my older, GPRS-only Simyo SIM, the response to AT+CPIN? is “SIM PUK2” after sending the PIN to the card, while it is “SIM PIN2” in the same situation with the newer UMTS-enabled Simyo SIM.
• chat(8) sucks badly, because it doesn’t seem to elegantly handle this case - no regexps, no if/then, every command sent needs to generate exactly one answer from the card, everything else is an error after timeout.
• When I do this more often, one of the now available flat rates (or, for starters, a 5 GB commitment tariff) for like 20 Euros becomes attractive.

Julian: You don't need autosuspend support to prevent UHCI from generating interrupts - you just need your hardware to be idle. The reason you're getting interrupts is that a USB device wants to send information. There's no way to get this information to the kernel without generating interrupts or polling - and polling is even worse, since it guarantees you'll be producing wakeups even when there's nothing to send.

If you're on a Macbook, the largest number of USB interrupts is probably from the Bluetooth controller. Either hciconfig hc0 down, or load hci_usb with the isoc=0 option. The other Macbook issue is that the trackpad will carry on sending updates even though there's no input - I wrote a patch to fix this, which ought to be in git now. These have nothing to do with the UHCI spec.

Why are C states so important? They allow the CPU to turn parts of itself off. However well designed your CPU, turning parts of the processor off is going to save power. Of course, this can only be done when the system is idle (code doesn't run so well on disabled execution units). It's also inevitable that there's going to be some latency in reenabling these portions of hardware, so you only want to enter them if you know that the processor is going to be idle for a significant (like 20ms or more) amount of time.

In C4 state, a modern Intel CPU will draw somewhere in the region of a Watt. There's absolutely no reason why a modern desktop shouldn't be spending most of its time idle, so we should aim to be hitting C4 as much as possible. It's low hanging fruit, and Powertop lets us identify most of the things preventing us from getting there. Processors are always going to be able to save power if they're idle. It's an entirely worthwhile project.

For what it's worth, the ULV Core 2s will max out at about 10 Watts, which isn't bad - sadly the Macbook Pro contains a T7600, which goes up to 34W. The last-generation Powerbook G4s with 7447As drew in the region of 20 Watts - Apple seems to think its customers prefer performance to low power consumption, and I don't think you can blame Intel for that (especially since you can get an LV 1.6GHz Core 2 Duo with a TDP of 17W, giving you rather more performance than the G4 Powerbook while consuming less power)

The main reason for the lack of activity during this week was that I had some problems with my router, a NSLU2 running the debian arm port. This was the machine I wanted the softfloat rrdtool I was talking about in these 2 posts.

It turns out that for some weird reason the USB controller of the slug resets when there is too much traffic going on. I got lots and lots of messages like:


$ grep reset -A 1 /var/log/syslog grep -E '(reset repeated)'
Aug 3 07:02:27 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
...
Aug 3 11:50:29 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:51:03 ritter last message repeated 4 times
Aug 3 11:53:15 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:53:46 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:55:48 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:56:07 ritter last message repeated 2 times
Aug 3 11:56:52 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:56:57 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2


That wouldn't have been a problem as long as the damn thing worked, but in some cases after the reset the root filesystem was lost and all the services running on the machine died (except the networking itself since all of that is part of the kernel and is loaded in memory).

It took me about three evenings to get to this conclusion (imagine being locked out of a machine which advertised running ssh, http, and dns services, being able to telnet and getting a respons, but the full protocol failed).

It all became more clear when, while being connected via ssh I got his result:

eddy@ritter ~ $ ls
-bash: ls: command not found

"WHAT?" was the first reaction, then I figured that life without ls is unbearable and came up with this bit:

alias ls='for I in * ; do echo $I ; done'

Quite cool to understand a little bit about the system. Still, cat was unavailable so having /proc and /sys available did not help that much. At some point I was thinking about a busybox shell, tried that, it didn't work since it wanted to remove some important bits like the initramfs tools.


I googled again and found a good starting point for a discussion of the same problem someone else was having. I ended up trying all the proposed solutions: rmmod-ing ehci-hcd, blacklisting the module, regenerating a initrd image with the blacklisted module... None of these worked (individually) and I ended up having an even more unstable system when ehci was not present (I was loosing the root FS after aprox. 1 min after logging in remotely immediately after start). Restoring the image with ehci was a pain (not to mention the time spent trying to figure a way to revert the change safely, since bricking the machine was not out of the question - imagine loosing the FS while flashing the ram drive image).

I finally managed to revert the ehci enabled image and tried the workaround proposed in this gentoo BR. I tried 128 and now I am at 64 and I am still getting those resets; Still something good came out of this, I followed Michael Prokop's Use root=UUID on NSLU2 article and I think I have now a stable root file system just thanks to him.

Now I am stuck:


grep -E '(max_sect reset)' /var/log/syslog
Aug 3 07:02:27 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 08:27:38 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 08:38:43 ritter manual message: max_sectors was set to 128
Aug 3 08:55:25 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 09:31:47 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 09:54:11 ritter set_max_sectors: max_sectors was set to 128
Aug 3 10:09:32 ritter set_max_sectors: max_sectors was set to 128
Aug 3 10:15:27 ritter set_max_sectors: sda's max_sectors was set to 128
Aug 3 10:24:24 ritter set_max_sectors: sda's max_sectors was set to 128
Aug 3 10:38:12 ritter set_max_sectors: sda's max_sectors was set to 128
Aug 3 10:47:04 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 10:48:27 ritter set_max_sectors: sda's max_sectors was set to 64
Aug 3 11:04:36 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
Aug 3 11:06:16 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2
....
Aug 3 15:05:58 ritter kernel: usb 3-1: reset high speed USB device using ehci_hcd and address 2

Should I try setting to 32?

In case you're wondering, I am doing the setting with this script:

#!/bin/sh

MAX_SECTORS=64
DISK=$(ls -l grep 'uuid.* / ' /etc/fstab awk ' print $1; ' sed 's#.*/\(.*\)$#\1#' tr -d '[0-9]')

[ -z "$DISK" ] && logger -t 'set_max_sectors' "error: could not detect root disk" && exit

echo "$MAX_SECTORS" > /sys/block/$DISK/device/max_sectors
logger -t 'set_max_sectors' "$ DISK 's max_sectors was set to $ MAX_SECTORS "

exit 0


Dear (not at all) lazy web, what can I do to fix/workaround this issue? Any help would be gratly appreciated (personal mail or comments).

Note: I am reluctant to try the fix proposed in the last comment that claims to fix the issue since compiling an arm kernel natively is a pain and I would like to have an official kernel from Debian Etch, as I do now.

Say you have a virtual machine at one of the larger hosting companies. You're sharing a system with some unknown number of other users. Wouldn't it be nice to be able to chat with people from the other VMs on the machine? Assume that the hosting company doesn't particularly want you do to this; they prefer you don't know that the machine's CPU is split 30 ways and that you're migrated to a new, random machine every night at 3 am. I wonder how to accomplish this? The coolest hack would be to frob some kind of available on-machine data source that the other users could watch. This basically requires finding and exploiting a minor security hole, though. Maybe a centralised registry would be better, if there's some way to uniquely identify a given host machine from inside the VM. Focusing on xen, I think enough data is leaked to make this possible.

• /proc/cpuinfo
• uname -a
• /sys/hypervisor/compilation/*
• /sys/hypervisor/properties/*

This should at least narrow it down to a set of similar boxes at a given hosting company, and then you can start looking at the network..

---

On a not-unrelated note, this diversidial system is way cool. 300 baud via telnet! I especially like the use of an ipod as a tape drive for booting the Apple IIe.

xorg and openoffice.org started with a cleanup of their bug reports. It is really great that compared to 2-3 years ago major cores of the Debian OS in unstable are quite in sync with upstream. Thus it is easy to forward to upstream the interesting part of bugs. The linux-2.6 bugs count reached that weekend almost 850 open bugs. Seeing that it gets unmanageable I'll decided to get it down to a target of 100 bugs. I'll blog from time to time about the progress. The process consists of pinging quite some bug reports against old Linux images and closing a huge swap of duplicate or no longer relevant bug reports. I expect the signal to noise ratio getting better once the bug count gets denser. The current side effect was to forward 1 patch upstream and to get 2 easy low hanging fruits fixed in latest linux-2.6 trunk. Thanks to enabling CONFIG_BLK_DEV_IO_TRACE trunk gains support for the blktrace(8). blktrace does direct IO block layer tracing - see also blktrace guide.

I just uploaded the 0.5 release of the newsbeuter RSS feed reader to unstable.
Apart from improvements in HTML rendering and lock file handling the new release:

• adds unicode compatibility


• a new filter language


• support for notifications

and finally you are also able to freely configure all key bindings.

The new filter language is pretty cool, you can now filter feeds for title, url, author etc. (see the documentation for all fields) using regular expressions like:
rssurl =~ "^http:\/\/nion\.modprobe.*", you can use the comparison operators and you are able to logical connect them.

The regexp support also enables you to killfile certain articles using the new ignore-article option, ignore-article "*" "title =~ \"SuSE\"" for example ;-P (press F to try it out)

With the notification support you are allowed to execute a specified program if a new article arrives, easy and useful for blog junkies.

Hopefully newsbeuter will become a good alternative for raggle and snownews users now as the snownews author is not really working on it anymore and raggle seems to have a stalled development as well.

A couple of days ago the hardware that is used to host this blog was upgraded - doubling the amount of RAM in the machine. To do this the machine was halted, memtest86+ was run to ensure that the new RAM worked correctly, and then it was booted up again. During that process my ssh session was not stopped! I merely refrained from typing anything until the upgrade was complete. This is one feature I really like about Xen. It can save the memory image of a running domain to a file and then restart it later. TCP sessions remain open if timeouts have not elapsed. The command xm save can be used to save the state to a file and the command xm restore will restore it. In Debian the location of the save files is stored in the file /etc/default/xendomains with the variable name XENDOMAINS_SAVE and defaults to /var/lib/xen/save. A quick experiment with one test domain (running Debian/unstable in 128M of RAM and had just run apt-get dist-upgrade so the memory contents would not be all zeros) showed that gzip -9 would decrease the file to 35% of it’s size at a cost of just over 1 minute of CPU time on a Pentium-M 1.7GHz. But gzip -3 compresses it to 37% and only takes 9 seconds. 9 seconds of CPU time to save 80M of disk space seems a reasonable trade-off. In my particular case it saves CPU time as the encryption I use for my root filesystem takes more CPU time than gzip -3 so compressing the data saves time. But I don’t expect my case to be common. Now when Xen is used on a more modern machine with a faster CPU gzip -3 has the potential to save time as well as disk space. A machine with a CPU that is in aggregate 10x faster than my laptop (I think that means most 64bit multi-core CPUs) running with a single S-ATA disk (that will have a sustained contiguous read speed of 80MB/s and write speed that is less) will save time when saving multiple Xen DomU’s if it runs them in parallel and compresses them. Also gzip is not the fastest compression program. There may be other options that are better suited to the needs of Xen. I have filed a Debian bug 435406 requesting that compression be supported.

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Firstly for the benefit of people who haven’t heard of it, the Advogato FAQ and the Wikipedia Page describe what Advogato does. Pete Zaitcev posted a strange article about me to Advogato. In it he accused me of “pumping hateful leftist propaganda into Advogato“, said propaganda being my regular blog posts. In an addendum he accused me of insanity, and said that my “attacks” were “divisive“. I considered writing an Advogato post in response but first read the Posting Guidelines which say:

• Please keep articles about Advogato itself to a minimum


• Personal complaints, rants, and flames belong in your blog, not here

Both of those criteria rule out Pete’s post and any response that I might make would risk being in breach of such conditions - so I will use my blog as the Advogato admins recommend. Pete’s ad-hominem attack on me claiming that my posts are hateful is bizarre. Pete, for the benefit of all the interested onlookers could you please inform us which of my posts you consider hateful and why you have such an opinion? As a general rule you should always cite articles that you reference. When you make accusations without any evidence to back them up it makes you look bad and prevents any positive discussion of the acts in question. As for the accusation of being divisive, that only happens when people are forced to choose sides. For example when you encourage other people to rate me down on Advogato because of my political opinions that can divide the community (in a small way, neither you, nor me, nor Advogato is important enough to cause a serious problem in this regard). The idea that I was intentionally pumping anything into Advogato was also strange to me. When I entered the URL for my blog into the Advogato settings page I didn’t even realise that it was being syndicated until I reviewed my web logs some time later. It seems that Advogato only has a small number of readers, a recent post about strange ZCAV performance included a graph and judging by the referrer tags it seems that 412 people read the post from Advogato out of 10468 total (so Advogato gets less than 4% of my readers). Planet Debian seems to get more than 15x the number of readers of Advogato. Incidentally if you don’t currently include images in your blog the reader tracking ability is one reason for including an image in an occasional post. Another strange ad-hominem attack was the reference to “college indoctrination“. When I was in university I supported the Liberal party (the Australian equivalent of the Republican party in the US). The influence of Linux programmers (including some of Pete’s colleagues at Red Hat) had much more of an effect on my political opinions than that of my university experience. I am not criticising Pete for disagreeing with me in regard to politics (I don’t even know what he disagrees with). Here are my specific criticisms of Pete’s behaviour:

1. Ad-hominem attacks


2. Encouraging mis-use of Advogato trust metrics for political reasons (this one may not have been deliberate)


3. Non-specific accusations which do not allow me to either defend myself against the accusations or change my actions if he turns out to have any reasonable points


4. Hypocrisy - he breaks two of the posting guidelines for the purpose of criticising my blog posts which supposedly break some unwritten rule


5. Not reading the Advogato FAQ - it has a specific section about political disagreements

But I’m not going to advocate voting him down on Advogato. He does write some interesting things on occasion. Check out his page on guns for example.

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I've been using quilt a lot at work recently (in a non-Debian environment), and I've been enjoying it very much. So much that I've decided to convert my Debian packages to it, from dpatch. Once you're used to quilt, using dpatch is almost literally painful. :)

There doesn't seem to be a ready-made guide on how to convert packages from dpatch to quilt, so here's how to do it painlessly in five easy steps:

1. Install the quilt package (duh) and make sure that the QUILT_PATCHES variable is set to debian/patches in your shell environment. Or you can set it in your ~/.quiltrc file instead (see this post for other interesting settings).
2. Delete the build dependency on dpatch from your debian/control file, replacing it with a dependency on quilt (>= 0.40).
3. In your debian/rules file, include /usr/share/quilt/quilt.make instead of /usr/share/dpatch/dpatch.make.
4. Convert all your dpatch files by using the following command from your package's top level:

   for p in $(dpatch list-all); do \
       quilt import -P $p.diff debian/patches/$p.dpatch; \
       quilt push; \
   done

5. Delete dpatch files:

   rm -f debian/patches/00list debian/patches/*.dpatch

And that's pretty much it! You'll probably want to clean up the headers of your debian/patches/*.diff files since they'll still contain some dpatch markers. You can now build your package as usual. To edit a patch, use quilt push <patch>, quilt edit <file1> <file2>, finish with quilt refresh to save the patch.

For more information on how to use quilt, read the tutorial, it's in /usr/share/doc/quilt. You won't regret switching!

I just flushed a bunch of updates.I started regression testing for qemubuilder.Nothing special, really.

In a comment on my blog post titled Childhood, Don Marti refers to an earlier blog post he wrote which refers to a New York Magazine article about the effects of praising children. The article does in some depth to describe scientific research into the issue of praising children for being “smart” vs praising them for working hard - with the conclusion being that it’s significantly better to praise them for working hard! One quote from that article that I find very significant is “Baumeister has come to believe the continued appeal of self-esteem is largely tied to parents pride in their children s achievements: It s so strong that ‘when they praise their kids, it s not that far from praising themselves’“. This matches my theory about people who subject their children to TV documentaries about gifted children. The conclusions regarding children seem quite clear and the article provides direct advice to parents and teachers as to how to avoid the problems. One issue I am wondering about after reading the NYM article is whether being exposed to smarter children hurts a child’s learning ability. The fact that there is no correlation between high self-esteem and learning ability has been proven, but the reports do not indicate whether there might be a correlation between a decreases in self-esteem and a decrease in learning ability. I recall pointing out to one the few good teachers at high-school that having some of the most capable and some of the least capable students in the same class was inefficient and led to excessive boredom for the more capable students and excessive difficulty in keeping up for the less capable students. I was told that “streaming” was considered bad because it was bad for the less capable students to know their status. I was also refused access to my results of the Westpac Maths contest for the same reason - which seems particularly strange, I was in the training program for the International Mathematical Olympiad so I doubt that releasing my score from one maths contest would change anyone’s opinion of my ability. I am also wondering about how this effects adults (apart from their education history). Should we try to praise work colleagues for their effort instead of being smart? Are adults discouraged from trying hard at their work when they see others succeeding with little apparent effort? One data point for this seems to be kernel coders in the Linux community. Everyone sees super-star Linux kernel coders on stage (on a pedestal) at conferences and it’s easy to believe that such people are significantly more intelligent than others (the well-known programmers are indeed very smart - but they also work a lot harder than most people believe) and that being so smart is a necessary pre-condition for submitting Linux kernel patches. I have met many people who appear to have the ability to be good at any type of coding but seem intimidated by kernel coding it for these reasons. Statements such as “I’ve been doing Linux coding for 10 years but I’m not a kernel coder” are often heard at Linux conferences. Also people who’s skills are respected are often regarded as kernel coders without any real reason. The Linux kernel is a large C program with limited options for a debugger, if you are good at C coding you should do OK! I know that I am trivialising the issues related to kernel coding, there are some tasks such as reverse-engineering device-drivers and debugging some of the tricky race conditions that require special skills - but no-one is born with such skills! I would not suggest that someone try a significant kernel coding task on their first attempt - as with all areas of programming it’s best to start with the easy things first. The web site kernelnewbies.org is a good source of information for people who are getting into kernel coding. I wonder whether a change in the attitudes towards such things could encourage more people to write free software, and more of the current programmers to attempt new challenges (such as kernel coding).

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I am subscribed to the Google news alerts for the keyword Debian, and usually this means that I am notified of every security upgrade at least three or four times (needlessly, since I'm subscribed to Debian's security announcements anyway...) But today, two headlines sparked my interest: One, Carla Schroeder wrote an introductory article into building Custom Linux kernels with Debian and Fedora (though why somebody would want to do this is beyond me...), showing how easy the process is (I may be biased, but I find Debian's way is easier. On the other hand, it within the -- rpm -- package framework instead of a custom command -- make-kpkg in Debian -- feels more consistent and logical. Without reading documentation you won't get anywhere on both systems, so it probably doesn't matter...) One down for Carla, however, for not doing enough basic research: “The new naming convention [linux-* instead of kernel-* packages] opens the door to using other kernels with Debian, which I don't know what those would be, but Debian is ready for them.” Or one down for us, the Debian project, for not making enough noise around the various non-Linux ports. Though that will come when GNU/kFreeBSD is released with lenny... Two, Debian derivative SimplyMEPIS, which switched to Ubuntu as a base operating system a year ago, is now returning to Debian GNU/Linux as its base system. The main reason seems to be long term stability and upgradeability - which is a key strength of Debian for many other users as well (me, for one.) The reason for switching to Ubuntu in the first place has been newer application versions and predictable upgrade schedules (and that Warren Woodford misunderstood how Ubuntu LTS was to be maintained, apparently) -- both issues are being addressed within Debian as we get better release management and faster integration of new application versions (the big pieces of software I use regularly are the Linux kernel, X.org, KDE and OpenOffice.org, all of which I find are integrated in unstable fast enough, and much faster than 2 years ago. That the testing migration sometimes takes time is not a problem since mixing etch, lenny and sid is usually possible without problems even in a production (desktop) environment.) So, if we take a step back from the day-to-day squabbling between developers working at cross purposes and look at the output we produce, I believe we're still doing some things right.

Russell Coker has recently started posting random tech-tips and recipes in his blog :

To improve things in this regard I plan to increase the number of posts I write with solutions to random technical problems that I encounter with the aim of providing a resource for google searches and to randomly inform people who read my blog.

This is nice to see on Planet Debian - although I hope we continue to see the personal entries. For anybody else who is considering posting things like this I would be delighted if you'd copy them to the Debian Administration website. There have been numerous times when I've been just about to write something on a topic, seen it posted elsewhere and figured I shouldn't do so:

• Because it would be duplication.
• Because it would look like plagiarism

(Notable examples off the top of my head: Introduction to OpenVZ, Introduction to GIT, several Xen pieces.) I don't get many submissions, which I'm getting resigned to, but it is easy and people really really are greatful for new posts. In other news linuxlinks.com are a bunch of spammers and will be reported as such. I utterly fail to care that they've added "my software" to their list; if I cared I'd join their site and agree to receive emails from them..

A response to a post I wrote about things to do for the environment suggested that there would be a health risk to lowering the temperature of a home hot-water system to save power. I have just been reading about so-called tankless hot-water systems. The concept is that instead of keeping a tank of water hot (which means that you lose some energy due to the insulation not being perfect) you heat water when you need it. The down-side to this is that you need a moderate amount of power to heat water as rapidly as it’s used. The GoTankless.com products use between 11KW and 27KW of electricity. The early implementations of this idea used gas - the occasional carbon-monoxide problem with gas appliances makes me inclined to avoid them so it’s good that there’s an electric option. One of the benefits of the tankless system is that it runs the water at a lower temperature than a regular hot water system. For a tank storing hot water you have to run it at a temperature that kills bacteria (or at least dramatically inhibits their growth) - which means greater than 50C, but for on-demand water it’s safer to have it run at something close to the desired temperature (probably not much above 40C) and not use the cold tap. Lower temperature water avoids the risk of scalding for children and the elderly and if the “hot tap” is running at a good temperature for a shower then you can just turn it on, wait 30 seconds for the pipes to warm up, and jump in! Incidentally it really sucks the way most showers have the taps under or behind the flow of water, so if the water becomes too hot before you get in then you end up getting minor burns in the process of turning on the cold tap. I still think that solar hot water is the way to go. It apparently combines something like a tankless system on water that comes out of a tank heated by the sun. So during winter it operates like a tankless system but in summer you get more hot water than you can use. This web site about Solar hot water systems indicates that they have a similar technology to “boost” solar hot water, so if the Sun doesn’t make the water hot enough then it can use electric or gas systems to further heat the water. It’s also interesting to note that they offer Heat Pump hot-water systems, it’s a pity that they apparently don’t support combining this with solar heating. Another interesting feature is what they call the Water Guardian that pumps cold water from the pipes back into the water tank and avoids wasting the water that you might otherwise run down the sink while waiting for it to get hot.

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Chris Samuel blogs about a plan to censor porn from the Internet in Australia. According to the ZDNet article the Fundamentalist Christian party Family First wants a national porn filter to protect children. However there is strong evidence to suggest that the incidence of rape decreases as the availability of pornography increases. Access to porn prevents rapes! The question is whether protecting people (mostly women and children) from rape is more important than protecting the strange and unusual (by the standards of modern Australian society) religious beliefs of a minority of people who oppose porn. The current research on porn vs rape is based on comparing different regions of the US with different levels of Internet access. It would be more accurate if a scientific test could be performed in a controlled environment. The US has the largest number of prisoners of any country and the largest proportion of the population in prison of any first-world country and rape is common in prison. It would be easy to grant access to porn to one cell block of a prison and deny access to another and then record the incidence of reported rape (currently in the US porn is restricted in prisons and masturbation in prison is a crime). The results of such research could be used to devise government policy with the aim of protecting people from rape. Of course that would require compassion - something that’s extremely uncommon in politicians particularly the ones that claim to be Christian. Some people are requesting the creation of Christian Porn - so Porn and Christianity don’t have to be opposed. The same site has an interesting page Masturbation: God’s Great Gift to Us. Now if all those rapists could be encouraged to watch Christian Porn and take advantage of God’s Great Gift then the world would be a better place.

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I've been busy doing various things, so I've not had a chance to blog much lately. Time for a quick catch-up... We've had a bit of a development panic at work, so I've been working longer hours than normal. The scary thing is (and I've noticed this in the past too), I seem to enjoy the job more when there's real pressure involved. That's not to say I want it to always be stressful, but we've had more fun with a small group of us really concentrating on a single project, working well together. Outside of work, I've been really quite relieved to take a bit of a break from Debian stuff since Debconf has finished. Debconf (as always) was a really good way to be re-enthused about working on Debian, but it has taken me several weeks to get over it physically. I've finally finished upgrading all of my machines at home to Etch. In most cases it was easy, but the final one left was lump, the firewall/mail/web/foo server. I'd chickened out of upgrading it for quite a while due to the sheer number of services it hosts, and also the substantial amount of local config it therefore holds. In the end, things were thankfully mostly painless. The nice thing about doing the upgrade was that finally lots of new software has suddenly become readily available. Amongst other things, I've added iodine and openvpn, and now I'm looking into playing with voice over IP (probably Asterisk). My Nokia E70 has a VOIP client and wifi, so in theory I should be able to use my regular mobile phone as a voip handset on my wireless network at home and just get cheaper outbound calls. Yay! I visited my friend Matthew a couple of weeks ago, and also helped him upgrade/install his network of Debian machines. Unfortunately, his main workstation (dual AMD64 goodness) is still left just running Windows. BIOS/SATA RAID - just say NO! No matter what we did on that machine, we could not make it dual-boot XP and Debian without forcing him to reinstall it all from scratch. :-( The SPI board elections have just finished. Congratulations to the new mugs^H^H^H^Hmembers of the board, and best of luck in doing a good job. And comiserations to the people who lost - I'm sure most of you would have been good, useful board members too. We're having a final Debconf 7 wrapup meeting next weekend in York, where we're hoping to get the final conference report finished. There are a few more T-shirts to get finished and delivered to people and the sponsorship bags to go out, then it's all done for this year. It'll be good to meet up with people again anyway. Oh, and not long now until the big BBQ at my place. I've started getting some supplies in already, and I'm looking forwards to a bunch of geeks coming round to wreck my house again. Or something... *grin* Last but not least - I'm changing ISPs shortly. Noodles and Huggie have provided excellent service for nearly 3 years, but are exiting the business and moving on to other things. So I'll be moving my home ADSL back to UKFSN shortly. Hopefully the disruption will be minimal.

I recently received an email from RSA inviting me to read their blog (after having requested an evaluation copy of one of their products). They invited me to “join the conversation“. Often blogs are described as a “conversation” and I’ve been considering whether that analogy is appropriate. The Collaborative International Dictionary of English v.0.48 has the following definition: Usage: Conversation , Talk . There is a looser sense of these words, in which they are synonymous; there is a stricter sense, in which they differ. Talk is usually broken, familiar, and versatile. Conversation is more continuous and sustained, and turns ordinarily upon topics or higher interest. Children talk to their parents or to their companions; men converse together in mixed assemblies. There are instances of blogging that can approximate conversation when bloggers cite each other’s articles in turn and leave comments on each other’s blogs. But it’s usually not that continuous and sustained. An occasional patterin is that blogger A writes a post, blogger B writes a post disagreeing with it, blogger A comments on blogger B’s post, and that’s usually the end of it. Usually it’s just a case of multiple bloggers writing posts representing their own opinions with occasional references to other blogs and no sustained interaction. The blogging interaction seems to more closely resemble academics presenting papers with alternate solutions to a problem than a conversation. One factor that I believe defines conversation but which isn’t mentioned in the dictionary is that the parties involved have an equal standing. The comments section of a blog is not such a forum, the blogger has a significantly more powerful voice (at least in connection with their own blog) than the people who comment. Someone who posts a comment may have it deleted, and it if is left then a rebuttal in another post will be seen by a significantly larger number of people (the number of people who read comments on a post is a tiny minority of the people who read the post). This doesn’t preclude conversation between bloggers who are of equal popularity in a community, for example most readers of my blog come from Planet Linux Australia and Planet Debian so any blogger who is also syndicated on those sites has an equal voice to me. Another factor in conversation is whether responses are even read. Many blogs don’t accept comments and it’s never certain that a blogger will see a track-back from a blog that references one of their posts. When one party ignores the other (or appears to do so) then there is no conversation. I’m not aware of whether a conversation with RSA people would be possible. While their blog refuses to send content to my Planet installation I guess I’m not going to find out… Is the lack of conversation a bad thing? One problem with conversation is that it often degenerates into what GCIDE defines as talk, while that is good for a friendly mailing list (EG your local LUG) it isn’t so good for the exchange of technical information. A compounding problem for mailing lists is the number of posts that can not be interpreted without the context of a thread of discussion. This often makes mailing lists unreasonably difficult to use in the search for answers to technical problems. When reading google search results I will usually read blog URLs before mailing list posts as a blog post will usually stand alone and either give me an answer or be obviously not related to my problem - sometimes I have to read a dozen messages in a list discussion to determine that it’s not going to help me! To improve things in this regard I plan to increase the number of posts I write with solutions to random technical problems that I encounter with the aim of providing a resource for google searches and to randomly inform people who read my blog. I find such posts by other people quite useful, I often get inspired to implement a technology after reading a blog post about it - there are many things that have a low priority in my todo list because they seem difficult, a blog post that reveals them to be easier than expected and advises how to avoid common problems can really make a difference!

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Because of the social networking and needing-to-be-registered of it all, I had to sign up for another website to keep track of one of my friends' goingses-onses. The sign-up process reminded me of a circus freakshow of the "Step on inside -- if you dare! And buy a bottle of our snake oil!" (insert knowing, taunting laugh) variety. Tell me how PUMPED you feel after reading the comments they added after I filled in the various fields:

Email address: Nicely put!
First name: So that's what they call you!
Last name: Classy last name, I have to admit!
Username: Creative!
I agree to the Terms of Service: ...I dare you to un-click that!
End of registration: To make sure you're as awesome as you claim, please visit your email's inbox for our verification email (I'm positive that more exclamation points were ejaculated all over my screen at this point but I closed the window too quickly to be sure.)
Activation confirmation emancipation proclamation: Wonderful, the hardest part is now over! Time to Enjoy! (With a capital E!!!!)
It might as well have been written by Dr. Bronner himself:

Email address: Godliness!
First name: If I'm not for me, who am I? Nobody!
Last name: Enlarge the positive!
Username: WE'RE ONE! ALL-ONE! EXCEPTIONS ETERNALLY? NONE! ABSOLUTE NONE!
I agree to the Terms of Service: Warning! Keep Out of Eyes! Wash Out with Water! Don't Drink Soap! Dilute! Dilute! or Wet Skin Well!
End of registration: Whatever unites mankind is better than whatever divides us!
Activation confirmation ALL-ONE! clean sensation: WELCOME TO SPACESHIP EARTH!!