Earlier today, Conrad Sanderson released another bug-fix version 3.0.2 for the still fairly recent 3.0.0 version of his excellent Armadillo C++ template library for linear algebra. The new RcppArmadillo release 0.3.0.2 also appeared on CRAN this morning. Beside Conrad's bugfix in Armadillo itself, he also convinced us to unroll a change imposed by R: NDEBUG is now being defined unconditionally when compiling R packages. In Armadillo's case, this suppresses a number of useful things including bounds-checking. So we now undefine this symbol in the initial RcppArmadillo headers. Users can still set it manually, and/or define ARMA_NO_DEBUG. The short NEWS entry follows below.

0.3.0.2 2012-04-19
    o   Upgraded to Armadillo release 3.0.2
          * fixes for handling diagonal matrices
    o   Undefine NDEBUG if it has been set (as R does) as this prevents a
        number of useful debugging checks. Users can still define it or
        define ARMA_NO_DEBUG if they want a 'non-development' build

Courtesy of CRANberries, there is also a diffstat report for 0.3.0.2 relative to 0.3.0.1 As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.

LED Fireworks. Or, parent helpers go overboard My friend, Mike Ward, and I help out at our kids school by teaching 5th and 6th graders programming in conjunction with a Lego class. For several years, I was teaching Logo on ancient Apple II machines. The teacher had a great curriculum and the kids learned a lot, but this year we decided to switch things around and try them out on Arduinos. This spring, the kids are building a Lego display centered around a birthday party theme for the star elephant at the Oregon Zoo (Packy), who turned 50 last weekend. In a moment of fun, I suggested that perhaps we should have some fireworks, along with the presents and birthday cake. How hard could it be to wire up a couple of LEDs to an Arduino to make something that looked like fireworks? Selecting parts. Mike and I sat down to order some parts from Digikey. We found these nice, cheap, LED drivers from Sharp. Then we found a selection of LEDs from Cree along with current-programming resistors (12.7k ) to drive the LEDs at 20mA, and some bypass caps (0.1 F) to keep the parts happy. The LED drivers are simple shift registers, with separate clock and data. They have both input and output pins, so you can daisy chain them and drive as many as you like from a single pair of CPU pins. We figured 160 LEDs would be plenty, so we ordered 10 chips. The LED drivers came in a through-hole, DIP package; it seemed like we d be able to just stuff them into a breadboard and quickly wire things up. Prototyping the design The LED driver chips turn out to use a much finer pitch package than the usual 0.1 spacing. There s no way we could stuff them into a breadboard and quickly wire things up. Obviously, a bit more care while ordering would have uncovered this, but my experience with through-hole parts is limited to parts from the mid 1970s I soldered extension wires onto one chip to test the circuit, and managed to get one chip talking to an Arduino. Here s a short movie of that in action: You can see the LED driver chip sitting on a set of extension leads plugged into the breadboard. It s hooked to the SPI port on the Arduino board, with the clock set as fast as it will go. If you watch the video, you can see that the LEDs actually vary in brightness. They re actually being pulse-width modulated. Clocked at 2MHz, there s enough bandwidth in the SPI bus to drive 160 LEDs with 127 discrete pulse widths at nearly 100Hz (100 * 127 * 160 = 2032000). Is bread boarding practical? With the chip propped up on its extension wires, and the LEDs plugged in, the whole setup was not surprisingly fragile. Getting five of these chips wired up and running for the length of the Lego show (one day at school and two days at the zoo) seemed unlikely. So, we decided to build some custom circuit boards. Using the GEDA tools to make circuit boards My business partner, Bdale Garbee, and I build rocketry electronics through Altus Metrum. He s the hardware guy and I spend my weekends writing firmware for various micro-controllers. Of course, I use free software tools for the firmware, and Bdale uses the free gEDA tools for the hardware. I ve gotten vaguely familiar with those by helping Bdale review circuit diagrams and PC board layout over the years. So I figured I d be able to learn a bit more about them and come up with some designs. I decided to stick two LED drivers on each board. As the chips can drive each LED with up to 50mA of current, each board could potentially consume 1.6A at 5V. Sticking a linear regulator on each board capable of supplying that much current would have required a hefty heat sink. Instead, I decided to stick a mini USB connector on the board and use some cheap USB power supplies. Of course, there wasn t a pre-packaged schematic symbol or footprint for the LED driver, so I first had to construct those. But, with symbols for all of the parts I used available, I drew this circuit: Wiring up 32 LEDs It s really easy to draw wires showing 32 LEDs hooked up to each board. Actually selecting connectors that can be easily hooked up took a bit more time. The idea of crimping individual two-pin connectors for 160 LEDs didn t seem like fun, plus individual connectors were going to cost a small fortune (the best option I found would have cost about $0.40 per LED). Bdale suggested using ribbon cable with a crimp-on connector crimp a connector across the whole cable and then split out two-wire sets for each LED. I d still have to individually solder each LED to the wire, but on the board end, all I d have to do is crimp the connector on to the cable. Designing the circuit boards The gEDA tools separate schematic design and PCB layout into two separate tools; the schematic program, gschem, exports a netlist and set of components which the schematic program, PCB, can import. This sounded a bit clunky to me, as you have to re-export and re-import the schematic data into the PCB each time you make changes, but it seems to work reasonably well in practice. The first time the schematic data is imported to the PCB tool, all of the component footprints are simply stacked on top of one another. With those moved to sensible locations, the tool will show rats for each netlist. Having drawn the schematic with symbols that strongly resembled the actual components, it was pretty easy to work through the rats one at a time by painting copper on the board. I d noticed that all of the signals could easily be routed on one side of the board, so I flooded the back side with a ground plane to keep things quiet. The final circuit board design looks like this: Circuit boards. All Altus Metrum products are manufactured by Advanced Circuits, and we ve been quite happy with them. They offer a cheap and fast prototyping service through their barebonespcb.com site. These boards are two layers with no silk screen or solder mask. I uploaded my design and in a couple of days I got back some shiny circuit boards: The footprint I designed for the LED drivers turned out to have a very small gap between the pads for each pin and the ground plane. This lead to a couple of shorted pins in the five boards, which were pretty easy to diagnose as the LED driven by that pin would be stuck on. Here s another picture with the ribbon cable connected and an LED lit up: Mounting the LEDs I started by writing a small nickle program to simulate the trajectory of a ballistic fireworks shell followed by an explosion at apogee and subsequent ballistic tracks for the resulting pieces. I made the initial conditions of the launch somewhat random, and Mike and I sat and watched that draw things until we saw a couple that looked good . The output from that was a series of X/Y locations spaced uniformly in time. Mike used those to drill holes in a piece of acrylic from TAP plastics. He glued the LEDs into that with some white glue (so that we have a chance of getting them back out): A custom maple box? I spent last weekend visiting my father for his birthday. Meanwhile, Mike was busy back home building a case for the project. I got home and found that he had fabricated a solid maple case. It s beautiful, and holds all of the LEDs, boards, wires and a couple of 4-outlet USB power supplies. Here s a picture of the joint he made in the box corners: The finished product Here s the inside of the box: And here s a movie of the whole thing in action. It s missing 8 white LEDs; I hadn t ordered enough from Digikey. Downloading schematics and PCB artwork The hardware design is licensed under the TAPR Open Hardware License. It s all stored in git (of course):

git://keithp.com/git/hw/fireworks

All of the symbols I created are also available through git:

git://keithp.com/git/hw/keithp

Things I d do differently One of the frustrating things about moving atoms around instead of just bits is that once you ve got a physical artifact, it s really expensive to change it. There are a couple of minor things I would change if I were going to build more of these:

• Add mounting holes. Not having any way to mount the boards means that they re flopping around inside the cabinet. We ll probably find a way to tie them down somehow, but a couple of holes in the boards would have made that really easy.
• Increase the gap between the pin pads and the ground plane. The narrow space provided ample opportunity for solder bridges. I ve increased that spacing in the git repository version of the boards.
• Used a variable resistor for LED current control. With a fixed value, it s very difficult to adjust the relative brightness of the LEDs. Even though we used LEDs from the same series, the different colors have different apparent brightness.
• Used surface mount passives. We had bought through-hole parts when the plan was to build these on a breadboard, but soldering through-hole parts onto the board is more work than using surface mount parts. 0805 (or even 1206) parts are plenty large to solder by hand and are faster to deal with than having to fold leads, insert them into holes, flip the boards over, solder them down and trim the leads.
• Perhaps we went a bit overboard on this project

Things that worked well There were a couple of things that went better than I had expected:

• The gEDA tools aren t that hard to use. Constructing the circuit board really was a simple matter of painting with copper. If you can drive inkscape, you can make circuit boards.
• Advanced Circuits bare-bones PCB service. It was really cool to upload the output files from gEDA and have actual boards arrive in the mail a couple of days later.
• Building the boards. I really didn t expect all of the components to just fit in the boards; I figured I d mess up the footprints or drill sizes and end up kludging something onto the boards. Bdale did catch a small drill size on the LED driver pins, which I bumped up a bit, but other than that, all of the parts slipped in and soldered easily. Each board took about 10 minutes to put together.

I like App Engine, my wedding website runs on App Engine as well as a couple recent commercial projects. However, there are some annoyances that make a lot of the useful things I learned at Google not applicable.

1. Chunked responses
   App Engine doesn't have a way of doing chunked responses.
   1.5. Processing after sending the responseMy annoyance here is that I can't send an early response and wait for some resource. Say I want to do 5 url fetches that I cache for a short period of time. If I want to reply in 250ms, I want to use any of the results I've gotten and reply to the user. Then once the rest of the fetches come in, I want to put them in the cache, so they will come back quickly the next time.
2. Counters
   App Engine has crappy support for counters. You can shard your counters into the datastore: https://developers.google.com/appengine/articles/sharding_counters#counter_python or you can use taskqueues: http://blog.appenginefan.com/2009/10/non-sharded-counters-part-2-using-task.html . Now, how do you graph these counters over time, well, that is left as an exercise for the reader. Google has special datastores for stores and retrieving counters.
3. Backends
   Backends in appengine are versioned separately from frontends. This sounds like a good idea, but to run the devserver with backends, the backends need to be in the same source tree. Thus backends share the same url space. Backends also share the same app.yaml, so again the url space is shared. Thus, if you make a change that you want to coordinate between the frontend and the backend, you need to change the application version in app.yaml, then rename all the backends in backends.yaml. If backends are supposed to be in the same source tree as frontends, then they should be prefixed with the application version. If backends should be versioned separately from frontends, then they shouldn't share url handlers from app.yaml.
   3.5 Uploading backends is slow
   Each backend is uploaded through appcfg.py separately. So if you are crazy and have one backend per backend level, then you need to upload 4 copies of the source code each time the backends get updated.
4. Logging
   I want structured logs. Instead what you have to do is use the python logging module to write out human readable logs, then parse them out into the structure you want.
   http://code.google.com/p/google-app-engine-samples/source/browse/trunk/logparser/logparser.py
   

As a preemptive counter, 1.5 could be dealt with using backends and a background thread, except backends don't scale to the number of queries, so my use case above isn't fixed.

Samuel Thibault is a French guy like me, but it took years until we met. He tends to keep a low profile, even though he s doing lots of good work that deserves to be mentioned. He focuses on improving Debian s accessibility and contributes to the Hurd. Who said he s a dreamer? Checkout his interview to have some news of Wheezy s status on those topics. Raphael: Who are you? Samuel: I am 30 years old, and live in Bordeaux, France. During the workday, I teach Computer Science (Architecture, Networking, Operating Systems, and Parallel Programming, roughly) at the University of Bordeaux, and conduct researches in heterogeneous parallel computing. During the evening, I play the drums and the trombone in various orchestra (harmonic/symphonic/banda/brass). During the night, I hack on whatever fun things I can find, mainly accessibility and the Hurd at the moment, but also miscellaneous bits such as the Linux console support. I am also involved in the development of Aquilenet, an associative ISP around Bordeaux, and getting involved in the development of the network infrastructure in Bordeaux. I am not practicing Judo any more, but I roller-skate to work, and I like hiking in the mountains. I also read quite a few mangas. Saturday mornings do not exist in my schedule (Sunday mornings do, it s Brass Band rehearsal ). Raphael: How did you start contributing to Debian? Samuel: Bit by bit. I have been hacking around GNU/Linux since around 1998. I installed my first Debian system around 2000, as a replacement for my old Mandrake installation (which after all my tinkering was actually no longer looking like a Mandrake system any more!). That was Potato at the time, which somebody offered me through a set of CDs (downloading packages over the Internet was unthinkable at the time with the old modems). I have been happily reading and hacking around documentation, source code, etc. provided on them. Contribution things really started to take off when I went to the ENS Lyon high school in 2001: broadband Internet access in one s own student room! Since sending a mail was then really free, I started submitting bugs against various packages I was using. Right after that I started submitting patches along them, and then patches to other bugs. I did that for a long time actually. I had very little knowledge of all packaging details at the time, I was just a happy hacker submitting reports and patches against the upstream source code. At ENS Lyon, I met a blind colleague with very similar hacking tastes (of course we got friends) and he proposed me, for our student project, to work on a brlnet project (now called brlapi), a client/server protocol that lets applications render text on braille devices themselves. Along the way, I got to learn in details how a blind person can use a Unix system and the principles that should be followed when developing Accessibility. That is how I got involved in it. We presented our project at JDLL, and the Hurd booth happened to be next to our table, so I discussed with the Hurd people there about how the Hurd console could be used through braille. That is how I got into the Hurd too. From then on, I progressively contributed more and more to the upstream parts of both accessibility software and the Hurd. And then to the packaging part of them. Through patches in bug reports first, as usual, as well as through discussions on the mailing lists. But quickly enough people gave me commit access so I could just throw the code in. I was also given control over the Hurd buildds to keep them running. It was all good at that stage: I could contribute in all the parts I was caring about. People however started telling me that I should just apply for being a Debian Developer; both from accessibility and Hurd sides. I had also seen a bunch of my friends going through the process. I was however a bit scared (or probably it was just an excuse) by having to manage a gpg key, it seemed like a quite dangerous tool to me (even if I already had commit access to glibc at the time anyway ). I eventually applied for DM in 2008 so as to at least be able to upload some packages to help the little manpower of the Accessibility and Hurd teams. Henceforth I had already a gpg key, thus no excuse any more. And having it in the DM keyring was not enough for e.g. signing the hurd-i386 buildd packages. So I ended up going through NM in 2009, which went very fast, since I had already been contributing to Debian and learning all the needed stuff for almost 10 years! I now have around 50 packages in my QA page, and being a DD is actually useful for my work, to easily push our software to the masses So to sum it up, the Debian project is very easy to contribute to and open to new people. It was used during discussions at the GNU Hackers Meeting 2011 as an example of a very open community with public mailing lists and discussions. The mere fact that anybody can take the initiative of manipulating the BTS (if not scared by the commands) without having to ask anybody is an excellent thing to welcome contributions; it is notable tha the GNU project migrated to the Debbugs BTS. More generally, I don t really see the DD status as a must, especially now that we have the DM status (which is still a very good way to drag people into becoming DDs). For instance, I gave a talk at FOSDEM 2008 about the state of accessibility in Debian. People did not care whom I was, they cared that there was important stuff going on and somebody talking about it. More generally, decisions that are made through a vote are actually very rare. Most of the time, things just happen on the mailing lists or IRC channels where anybody can join the discussion. So I would recommend beginners to first use the software, then start reporting bugs, then start digging in the software to try fix the bugs by oneself, eventually propose patches, get them reviewed. At some point the submitted patches will be correct already most of the time. That s when the maintainers will start getting bored of just applying the patches, and simply provide with commit access, and voil , one has become a main contributor. Raphael: You re one of the main contributors to the Debian GNU/Hurd port. What motivates you in this project? Samuel: As I mentioned above, I first got real contact with the Hurd from the accessibility point of view. That initially brought me into the Hurd console, which uses a flexible design and nice interfaces to interact with it. The Hurd driver for console accessibility is actually very straightforward, way simpler than the Windows or Linux drivers. That is what caught me initially. I have continued working on it for several reasons. First, the design is really interesting for users. There are many things that are natural in the Hurd while Linux is still struggling to achieve them, such as UID isolation, recently mentioned in LWN. What I really like in the Hurd is that it excels at providing users with the same features as the administrator s. For instance, I find it annoying that I still can not mount an ISO image that I build on e.g. ries.debian.org. Linux now has FUSE which is supposed to permit that, but I have never seen it enabled on an ssh-accessible machine, only on desktop machines, and usually just because the administrator happens to be the user of the machine (who could as well just have used sudo ) For me, it is actually Freedom #0 of Free Software: let the user run programs for any purpose, that is, combining things together all the possible ways, and not being prevented from doing some things just because the design does not permit to achieve them securely. I had the chance to give a Hurd talk to explain that at GHM 2011, whose main topic was extensibility , I called it GNU/Hurd AKA Extensibility from the Ground, because the design of the Hurd is basically meant for extensibility, and does not care whether it is done by root or a mere user. All the tools that root uses to build a GNU/Hurd system can be used by the user to build its own GNU/Hurd environment. That is guaranteed by the design itself: the libc asks for things not to the kernel, but to servers (called translators), which can be provided by root, or by the user. It is interesting to see that it is actually also tried with varying success in GNU/Linux, through gvfs or Plash. An example of things I love being able to do is: $ zgrep foo ~/ftp://cdn.debian.net/debian/dists/sid/main/Contents-*.gz On my Hurd box, the ~/ftp: directory is indeed actually served by an ftpfs translator, run under my user uid, which is thus completely harmless to the system. Secondly and not the least, the Hurd provides me with interesting yet not too hard challenges. LWN confirmed several times that the Linux kernel has become very difficult to significantly contribute to, so it is no real hacking fun any more. I have notably implemented TLS support in the Hurd and the Xen and 64bit support in the GNU Mach kernel used by the Hurd. All three were very interesting to do, but were already done for Linux (at least for all the architectures which I actually know a bit and own). It happens that both TLS and Xen hacking experience became actually useful later on: I implemented TLS in the threading library of our research team, and the Xen port was a quite interesting line on my CV for getting a postdoc position at XenSource Lastly, I would say that I am used to lost causes My work on accessibility is sometimes a real struggle, so the Hurd is almost a kind of relief. It is famous for his vapourware reputation anyway, and so it is fun to just try to contribute to it nevertheless. An interesting thing is that the opinion of people on the Hurd is often quite extreme, and only rarely neutral. Some will say it is pure vapourware, while others will say that it is the hope of humanity (yes we do see those coming to #hurd, and they are not always just trolls!). When I published a 0.401 version on 2011 April 1st, the comments of people were very diverse, and some even went as far as saying that it was horrible of us to make a joke about the promised software Raphael: The FTPmasters want to demote the Hurd port to the debian-ports.org archive if it doesn t manage a stable release with wheezy. We re now at 2 months of the freeze. How far are you from being releasable ? Samuel: Of course, I can not speak for the Debian Release team. The current progress is however encouraging. During Debconf11, Michael Banck and I discussed with a few Debian Release team members about the kind of goals that should be achieved, and we are near completion of that part. The Debian GNU/Hurd port can almost completely be installed from the official mirrors, using the standard Debian Installer. Some patches need some polishing, but others are just waiting for being uploaded Debian GNU/Hurd can start a graphical desktop and run office tools such as gnumeric, as well as the iceweasel graphical web browser, KDE applications thanks to Pino Toscano s care, and GNOME application thanks to Emilio Pozuelo Monfort s care. Of course, general textmode hacking with gcc/make/gdb/etc. just works smoothly. Thanks to recent work on ghc and ada by Svante Signell, the archive coverage has passed 76%. There was a concern about network board driver support: until recently, the GNU Mach kernel was indeed still using a glue layer to embed the Linux 2.2 or even 2.0 drivers (!). Finding a network board supported by such drivers had of course become a real challenge. Thanks to the GSoC work of Zheng Da, the DDE layer can now be used to embed Linux 2.6.32 drivers in userland translators, which was recently ACCEPTed into the archive, and thus brings way larger support for network boards. It also pushes yet more toward the Hurd design: network drivers as userland process rather than kernel modules. That said, the freeze itself is not the final deadline. Actually, freeze periods are rests for porters, because maintainers stop bringing newer upstream versions which of course break on peculiar architectures. That will probably be helpful to continue improving the archive coverage. Raphael: The kfreebsd port brought into light all the packages which were not portable between different kernels. Did that help the Hurd port or are the problems too different to expect any mutual benefit? Samuel: The two ports have clearly helped each other in many aspects. The hurd-i386 port is the only non-Linux one that has been kept working (at least basically) for the past decade. That helped to make sure that all tools (dpkg, apt, toolchain, etc.) were able to cope with non-Linux ports, and keep that odd-but-why-not goal around, and evidently-enough achievable. In return, the kFreeBSD port managed to show that it was actually releasable, at least as a technological preview, thus making an example. In the daily work, we have sometimes worked hand in hand. The recent porting efforts of the Debian Installer happened roughly at the same time. When fixing some piece of code for one, the switch-case would be left for the other. When some code could be reused by the other, a mail would be sent to advise doing so, etc. In the packaging effort, it also made a lot of difference that a non-Linux port is exposed as released architecture: people attempted by themselves to fix code that is Linuxish for no real reason. The presence of the kFreeBSD is however also sometimes a difficulty for the Hurd: in the discussions, it sometimes tends to become a target to be reached, even if the systems are not really comparable. I do not need to detail the long history of the FreeBSD kernel and the amount of people hacking on it, some of them full-time, while the Hurd has only a small handful of free-time hackers. The FreeBSD kernel stability has already seen long-term polishing, and a fair amount of the Debian software was actually already ported to the FreeBSD kernel, thanks to the big existing pure-FreeBSD hackerbase. These do not hold for the GNU/Hurd port, so the expectations should go along. Raphael: You re also very much involved in the Debian Accessibility team. What are the responsibilities of this team and what are you doing there? Samuel: As you would expect it, the Debian Accessibility team works on packaging accessibility-related packages, and helping users with them; I thus do both. But the goal is way beyond just that. Actual accessibility requires integration. Ideally enough, a blind user should be able to just come to a Debian desktop system, plug his braille device, or press a shortcut to enable speech synthesis, and just use the damn computer, without having to ask the administrator to install some oddly-named package and whatnot. Just like any sighted user would do. He should be able to diagnose why his system does not boot, and at worse be able to reinstall his computer all by himself (typically at 2am ). And that is hard to achieve, because it means discussing about integration by default of accessibility features. For instance, the Debian CD images now beep during at the boot menu. That is a precious feature that has been discussed between debian-boot and debian-accessibility for a few weeks before agreeing on how to do it without too much disturbance. Similarly, my proposition of installing the desktop accessibility engines has been discussed for some time before being commited. What was however surprisingly great is that when somebody brought the topic back for discussion, non-debian-accessibility people answered themselves. This is reassuring, because it means things can be done durably in Debian. On the installation side, our current status is that the stable Debian installer has a high contrast color theme, and several years ago, I have pushed toward making standard CD images automatically detect braille devices, which permits standalone installation. I have added to the Wheezy installer some software speech synthesis (which again brought discussion about size increase vs versatility etc.) for blind people who do not have a braille device. I find it interesting to work on such topic in Debian rather than another distribution, because Debian is an upstream for a lot of distributions. Hopefully they just inherit our accessibility work. It at least worked for the text installer of Ubuntu. Of course, the Accessibility team is looking for help, to maintain our current packages, but also introduce new packages from the TODO list or create some backports. One does not need to be an expert in accessibility: tools can usually be tested, at least basically, by anybody, without particular hardware (I do not own any, I contributed virtual ones to qemu). For new developments and ideas, it is strongly recommended to come and discuss on debian-accessibility, because it is easy to get on a wrong track that does not bring actual accessibility. We still have several goals to achieve: the closest one is to just fix the transition to gnome3, which has been quite bad for accessibility so far :/ On the longer run, we should ideally reach the scenario I have detailed above: desktop accessibility available and ready to be enabled easily by default. Raphael: What s the biggest problem of Debian? Samuel: Debian is famous for its heated debian-devel discussions. And some people eventually say this no fun any more . That is exemplified in a less extreme way in the debian-boot/accessibility discussions that I have mentioned above. Sometimes, one needs to have a real stubborn thick head to continue the discussion until finding a compromise that will be accepted for commit. That is a problem because people do not necessarily have so much patience, and will thus prefer to contribute to a project with easier acceptance. But it is also a quality: as I explained above, once it is there, it is apparently for good. The Ubuntu support of accessibility in its installer has been very diverse, in part due to quite changing codebase. The Debian Installer codebase is more in a convergence process. Its base will have almost not changed between squeeze and wheezy. That allowed the Debian Accessibility team to continue improving its accessibility support, and not have to re-do it. A wiki page explains how to test its accessibility features, and some non-debian-accessibility people do go through it. A problem I am much more frightened by is the manpower in some core teams. The Debian Installer, grub, glibc, Xorg, gcc, mozilla derivatives, When reading the changelogs of these, we essentially keep seeing the same very few names over and over. And when one core developer leaves, it is very often still the same names which appear again to do the work. It is hard to believe that there are a thousand DDs working on Debian. I fear that Debian does not manage to get people to work on core things. I often hear people saying that they do not even dare thinking about putting their hands inside Xorg, for instance. Xorg is complex, but it seems to me that it tends to be overrated, and a lot of people could actually help there, as well as all the teams mentioned above. And if nobody does it, who will? Raphael: Do you have wishes for Debian Wheezy? Samuel: That is an easy one Of course I wish that we manage to release the hurd-i386 port. I also wish that accessibility of gnome3 gets fixed enough to become usable again. The current state is worrying: so much has changed that the transition will be difficult for users already, the current bugs will clearly not help. I also hope to find the time to fix the qt-at-spi bridge, which should (at last!) bring complete KDE accessibility. Raphael: Is there someone in Debian that you admire for their contributions? Samuel: Given the concerns I expressed above, I admire all the people who do spend time on core packages, even when that is really not fun everyday. Just to alphabetically name a few people I have seen so often here and there in the areas I have touched in the last few years: Aur lien Jarno, Bastian Blank, Christian Perrier, Colin Watson, Cyril Brulebois, Frans Pop, J rg Jaspert, Joey Hess, Josselin Mouette, Julien Cristau, Matthias Klose, Mike Hommey, Otavio Salvador, Petr Salinger, Robert Millan, Steve Langasek. Man, so many things that each of them works on! Of course this list is biased towards the parts that I touched, but people working in others core areas also deserve the same admiration.

---

Thank you to Samuel for the time spent answering my questions. I hope you enjoyed reading his answers as I did. Note that older interviews are indexed on wiki.debian.org/PeopleBehindDebian.

Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Google+, Twitter and Facebook.

3 comments Liked this article? Click here. My blog is Flattr-enabled.

Thanks to great SUSE Studio I've made available appliance with ready to run Weblate. It's based on openSUSE 12.1, with few packages coming from Python devel repository (where I had to push some package updates) and Weblate package, which is currently available in my home. After booting the appliance, you will get Weblate running as web service (it takes some time on first boot as database setup is done in that time). In case you will use it for more than playing, please remember to change default passwords as described in our documentation. Anyway let's stop talking, you can get the appliance at SUSE Studio Gallery.

Filed under: English Suse Weblate 2 comments Flattr this!

At a customer, I've migrated a number of manually-maintained servers to having them be maintained through puppet not so long ago. Since then, some more machines have been added, and getting them up and running properly was a breeze: do a base install, install puppet, sign the certificate, restart puppet, and then wait and twiddle thumbs while puppet did its magic. Easy as pie. Now, a few months later, we needed to install a number of windows machines for a lab (not my choice), and the person involved asked me to figure out some diskspace so we could start creating images for those. Not a chance. Instead, I suggested looking for a configuration management system, similar to puppet. Since we're using Samba 3 to run the Windows network here, dropping everything in Active Directory was not an option. But a short while later, he came back with the note that puppet, in its 2.7 version, actually does support Windows as a platform for the managed machines. Interesting. The unfortunate bit was that puppet supports creating files and installing software when it is distributed as an MSI file, but not when it's distributed as a .exe file. This is not unexpected; MSI files can be installed noninteractively; but when something is distributed as a .exe file, it means it needs to be installed interactively; and puppet does not have the ability to interact with GUI software. The workaround: use something that does have that ability (in my case, autoit), and use an exec block in puppet to make it call those scripts. In effect, that's a bit like screenscraping. Add a creates stanza to the block, so that the installer isn't started again if the software at hand has already been installed. This 'autoit' thing also comes with a recording utility, allowing one to create an initial script by just doing the installation, and having the tool just record stuff. With that, the machines are installed 99% automated. I say 99%, because there are still some issues:

• Some software ships with an embedded google toolbar and an embedded google chrome. Not only do we not want that, it also makes automatic installation a Very Hard problem: if you install the software the very first time, it asks you whether you want to install Google Toolbar. If you decline, the rest of the installation is shown, and a registry key is set. If you then uninstall and reinstall, the Google Toolbar question isn't shown; instead, the Chrome question is shown. If you decline that, then the same happens with a different registry key.
  Google doesn't actually document where these keys are set, or how it can be disabled for any software that might possibly have embedded toolbars or browsers. Or, well if it does document it, I certainly didn't find any documentation about it; the fact that google tells me "you're running Linux, you don't need Google Toolbar, go fuck yourself" when I go to the toolbar.google.com website isn't very helpful.
  Anyway, the keys are under HKLM\Software\Google. You can't miss them.
• This being Windows, sometimes the machine needs to be rebooted after an installation. The Windows Installer software, msiexec.exe, signals this fact by exiting with an exit state of 3010. Unfortunately, puppet doesn't understand that, causing it to mark the installation as failed, and retrying it on the next run. That's annoying.
• Sometimes, telling the machine to postpone rebooting causes the next installation to behave slightly differently, which will cause the autoit script to fail. When that happens, I need to kill autoit, exit the installer for the failed application, and allow puppet to finish. After that, and after a reboot of the machine and restart of puppet, everything works well.
• To be able to install software, Windows may sometimes need to kill some applications, or may need to take focus. This may interfere with the lab readings these machines will be used for, so is not an option. Instead, I've decided not to ever run puppet agent as a service, instead always calling it manually with the '--onetime' option, so it quits once the manifest is applied. Unfortunately, that makes it harder to update things; I'll have to walk by each and every one of the machines if I ever need to add something. I did consider adding that to a login script, but then the user logging in to the machine will most likely not ever have the required privileges to actually do what puppet needs done.

I'll have to think about this some more, I guess. First, it's clear that while puppet does have some Windows functionality, it's not entirely ready yet. And somehow, using autoit to add to Puppet functionality feels like an ugly hack. We'll see what the future brings.

Pretty much on schedule, Weblate 0.9 has been released today. Besides dozen of bug fixes, the project has been changed to recommended file layout for Django 1.4. In case you are upgrading you will need to adjust few bits, please check documentation. Full list of changes for 0.9:

• Fixed import of unknown languages.
• Improved listing of nearby messages.
• Improved several checks.
• Documentation updates.
• Added definition for several more languages.
• Various code cleanups.
• Documentation improvements.
• Changed file layout.
• Update helper scripts to Django 1.4.
• Improved navigation while translating.
• Better handling of po file renames.
• Better validation while creating subproject.
• Integrated full setup into syncdb.
• Added list of recent changes to all translation pages.
• Check for not translated strings ignores format string only messages.

You can find more information about Weblate on it's website, the code is hosted on Github. If you are curious how it looks, you can try it out on demo server. You can login there with demo account using demo password or register your own user. Weblate is also being used https://l10n.cihar.com/ as official translating service for phpMyAdmin, Gammu, Weblate itself and others.

Filed under: English Weblate 0 comments Flattr this!

Another day, more patches. This time, it was to the rockn vibes of Chopped. Patch for:

• 667365 (s51dude)
• 667331 (prerex)
• 667328 (posterazor)
• 667313 (openmsx-debugger)
• 667308 (oggvideotools)

In the mean-time, I put together a script for GCC 4.7 transition bugs that are owned by the QA team with patches in the BTS. It s easy as cake to throw together a QA upload, so I encourage anyone out there to do some easy hacking :)

Google rant Seems venting can be a worthwhile once in a while; the content of this post made its way into Google. No promises of any kind were made, but it's good to know that this is getting some exposure within Google :) That was quick. moreutils et al Steve Kemp is right; moreutils is very useful in some situations. And yes, it's a pity that we all have our own scripts without a central repository to host them all. The problem is one of diminishing returns and information overload; if any given collection becomes too large, it becomes tedious to look through it. You may have the Most Awesome Ever solution to any given problem, but unless whoever needs it can find it quickly, it's useless to them. Thorsten Glaser suggested this collection, but it suffers from the same basic problem: Not enough content? You won't find what you need. Too much content? You won't find what you need. Finding the right balance is highly non-trivial. Linux storage Russell Coker shared yet another chapter of his continuing quest for modern, reliable, software-based storage on Linux. The short version is "ZFS is not that good on Linux while btrfs is not ready for prime time, yet." That's, unfortunately, not much of a surprise. fsck.btrfs is still too new and the lack of RAID 5/6 is an absolute show-stopper as far as I am concerned. COW solves the writing speed issues so, hopefully, that old argument can finally be laid to rest. And on top of the "wastng" of more disks for RAID 10, the minimum number of failed disks that can lead to data loss on RAID 10 is two whereas it's three for RAID 6. No-brainer, imo. Anyone who does not agree with Dell's pricing structure should seriously consider looking at SuperMicro, by the way. Cheap(ish), reliable, high disk densities. Password hashes Saku Ytti talks about password hashing and the relative merits of different algorithms. While I agree that bcrypt incorporates a good approach inasmuch it's designed to be slow to compute and can be made slower as needed, I think he focuses on one aspect while disregarding all others. Still, the premise that deterring brute force attacks on known hashes is the only concern is wrong. Avoiding collisions, reasonable certainty that there are no computational shortcuts, irreversibility, pseudo-random output, full use of the output's possible values, and thorough analysis by experts in the field are important concerns, as well. Brute forcing known hashes is hardly the only attack. When brute forcing a service, i.e. against an unknown hash, no matter if the system is remote or local, the computational cost of hashing is mostly irrelevant. Rainbow tables help mitigate computational cost when trying to extract clear text in case the hash is known. And if there are a lot of collisions or an easy way to find them, knowing the clear text password is not needed. Simply use whatever generates the correct output and you're done. Again, I am not saying that bcrypt is a bad idea; it's just that there are more concerns than computational cost alone. Travel If you know your way around Novosibirsk, please contact me. We have almost no idea what to do while there other than visiting the railroad museum; part of the reason why we are stopping there is to have a break after ~50 hours on the train and because Novosibirsk is just an awesome name. Our focus while there will be on seeing interesting industrial or research sites. Given that there are large industrial complexes and formerly secret cold war secret research cities situated around Novosibirsk it would be a pity not to see any of them. We may end up hiring a taxi via the hotel and having that drive us around a bit. Somewhat boring and potentially costly, but a feasible backup. Blogging frequency I have to admit being am a bit worried about spamming the various aggregators which are fed from this blog. Writing this catchall post is an attempt to mitigate this. While I am getting a surprising amount of positive feedback, I would be interested to hear anything negative, if applicable, as well. You know how to reach me.

Google seems to become more and more annoying. Package download http://dl.google.com/linux/chrome/deb/ is slow. Not just slow, but slow. Any random apt-get update will take ages; just sitting there waiting for Google's servers to send any data. Downloading actual packages is slow, as well. Ironically, Google's PageRank will punish sites for loading slowly; it's a pity they don't use their considerable server & bandwidth capacities to fix slowness they are causing, themselves. Chrome Copy and paste is a central part of what I use a mouse for. X has had two copy buffers for as long as I can remember, one for mouse selection, pasting with middle mouse button and one for CTRL-c/CTRL-v. Chrome merges the two. That's bad enough in and as of itself, but every time Chrome gets focus, it will clobber anything you may have in your copy buffers at that time with anything that's selected. No matter if you selected it via mouse, via keyboard, a context switch autoselected something. Selection goes into buffer. Every time. Every. Single. Time. To add insult to injury, this is dependent on which tab is active. And if you happen to search on the site (CTRL-f), it will always use what's in the search bar to clobber buffers, no matter if anything on the actual website has been selected. I can't find the bug report about this at the moment, but Google's stance is that this is a feature and introducing an option for traditional copy & paste handling is not desirable. Google+ I get that they feel a need to combat Facebook, but still, pushing Google+ on you is just annoying. At least the Android application has had a permission change on ICS so it can not auto-update. It's the little things ;) WWW Unified branding, the need to support touch-based devices in their UI, etc. Still, GMail's new interface sucks and the old one will be going away for good. And while making some UI elements larger or displaying them unconditionally makes sense for hand-held portrait displays, this is highly annoying on wide-screen landscape displays. 1366x768 may have overtaken 1024x768, but 768 is a constant here and still not a lot. As an aside, hopefully the Apple Effect and the iPad 3 will break the age-long stalemate with regards to screen resolution. More is better, here. Android Bloatware Using stock Android means you won't get Facebook and other useless apps pre-installed. Yet, uninstalling stock applications, like Google+, is impossible. Rights management It's nice that I get to see what kind of access an application would like to have. It's not nice that I can not choose what access I am willing to grant any given application. I can make a binary decision, install or not install, but I can't refuse random access rights to applications. There are custom versions of Android out there which allow you to do this and many applications seem to cope with being unable to do some things. This should be a standard feature. Access management The concept of "access to USB storage" meaning "whatver your SD card or, in the Galaxy Nexus' case, just a specific directory" is also broken. There is a middle ground between "this application needs access to a large chunk of storage" and "this application needs complete access to said large chunk". Just assign the application a specific directory to write into and read from and done's done. Multi-user I can not hand anyone my phone to play a game or surf the Internet without giving them the ability to look through all my email, contacts, calendar, you name it. While I only give my phone to people I trust completely, this still sucks. How hard can it be to create a minimal guest mode which allows people to access a few pre-selected applications with a custom setting of if they are allowed to use cellular data and/or WiFi? Data access Authorized Access Ah, the big one.... Keep in mind that I am using Google's latest and greatest, the Samsung Galaxy Nexus GSM. It's as cutting-edge as you can get. Yes, having one continuous storage device is nice. But MTP support on Linux is abysmal and you are forced to access your data by means of MTP or PTP. gphoto2, gwenview, and gthumb are all unable to import any photos via PTP; no program I tried can transfer anything via MTP. gphoto2 will transfer the background images which APOD (highly recommended, by the way; there's also a donation application for this) stores on my phone. That's it. So, unless I send email to myself, use WiFi-based hacks, or root my phone, I can not access my data. On the strongest mobile platform in the world. Using the most powerful and versatile OS with up-to-date packages. In 2012. Yay. Unauthorized Access Not being able to access my data is a Bad Thing. Even worse is when others can access my data. Contrary to older Android versions, someone decided that it would be a good idea to allow MTP or PTP, only. As in "you can not disable MTP and PTP. One of them has the be activated." This is awesome when you want to charge your phone at an airport or at an acquaintance's possibly malware-ridden Windows machine. Everyone and their bot-herder can potentially access my data while I can not. Usability And while MTP/PTP is an either/or decision, they are using check-boxes, not radio buttons. There's a decade or more of UI experience about check-box versus radio button, so why not use it? I know of at least one owner of a Galaxy Nexus who was not even aware that he couldn't turn off MTP (the default) as the UI pretends otherwise. Opaqueness And good luck trying to contact anybody about this. Having filed a few bugs against Google stuff in the past, I simply gave up on it. Back when Gmail's mailing list filtering and labelling system was somewhat broken, I spent months hunting down people who knew people who knew someone who was able to actually do something about it.

Since some years, there has been a movement towards standardization: mobile devices are now using Micro-USB for data transfer and charging, and SD or Micro-SD for storage extension (except Apple of course). One piece is lacking to this perfection, however; as far as I know, digital camera producers did realize that SD won for storage, but they do not seem to have acknowledged the Micro-USB standard yet. Now, since manufacturers and resellers do not indicate the connector type, I have no way to be sure that this is still the case. So, dear lazyweb, do you know if, by chance, there exists a compact digital camera that would use SD cards and a Micro-USB connector for data transfer and integrated charging?

One of my clients is currently investigating new hosting arrangements. It s a bit of a complex process because there are lots of architectural issues relating to things such as the storage and backup of some terabytes of data and some serious computation on the data. Among other options we are considering cheap servers in the EX range from Hetzner [1] which provide 3TB of RAID-1 storage per server along with reasonable CPU power and RAM and Amazon EC2 [2]. Hetzner and Amazon aren t the only companies providing services that can be used to solve my client s problems, but they both provide good value for what they provide and we have prior experience with them. To add an extra complication my client did some web research on hosting companies and found that Hetzner wasn t even in the list of reliable hosting companies (whichever list that was). This is in some ways not particularly surprising, Hetzner offers servers without a full management interface (you can t see a serial console or a KVM, you merely get access to reset it) and the best value servers (the only servers to consider for many terabytes of data) have SATA disks which presumably have a lower MTBF than SAS disks. But I don t think that this is a real problem. Even when hardware that s designed for the desktop is run in a server room the reliability tends to be reasonable. My experience is that a desktop PC with two hard drives in a RAID-1 array will give a level of reliability in practice that compares very well to an expensive server with ECC RAM, redundant fans, redundant PSUs, etc. My experience is that the most critical factor for server reliability is management. A server that is designed to be reliable can give very poor uptime if poorly maintained or if there is no rapid way of discovering and fixing problems. But a system that is designed to be cheap can give quite good uptime if well maintained, if problems can be repidly discovered and fixed. A Brief Overview of Managing Servers There are text books about how to manage servers, so obviously I can t cover the topic in detail in a blog post. But here are some quick points. Note that I m not claiming that this list includes everything, please add comments about anything particularly noteworthy that you think I ve missed.

1. For a server to be well managed it needs to be kept up to date. It s probably a good idea for management to have this on the list of things to do. A plan to check for necessary updates and apply them at fixed times (at least once a week) would be a good thing. My experience is that usually managers don t have anything to do with this and sysadmins either apply patches or not at their own whim.
2. It is really ideal for people to know how all the software works. For every piece of software that s running it should either have come from a source that provides some degree of support (EG a Linux distribution) or be maintained by someone who knows it well. When you install custom software from people who become unavailable then it puts the reliability of the entire system at risk if anything breaks then you won t be able to get it fixed quickly.
3. It should be possible to rapidly discover problems, having a client phone you to tell you that your web site is offline is a bad thing. Ideally you will have software like Nagios monitoring the network and reporting problems via a SMS gateway service such as ClickaTell.com. I am not sure that Nagios is the best network monitoring system or that ClickaTell is the best SMS gateway, but they have both worked well in my experience. If you think that there are better options for either of those then please write a comment.
4. It should be possible to rapidly fix problems. That means that a sysadmin must be available 24*7 to respond to SMS and you must have a backup sysadmin for when the main person takes a holiday, or ideally two backup sysadmins so that if one is on holiday and another has an emergency then problems can still be fixed. Another thing to consider is that an increasing number of hotels, resorts, and cruise ships are providing net access. So you could decrease your need for backup sysadmins if you give a holiday bonus to a sysadmin who uses a hotel, resort, or cruise ship that has good net access. ;)
5. If it seems likely that there may be some staff changes then it s a really good idea to hire a potential replacement on a casual basis so that they can learn how things work. There have been a few occasions when I started a sysadmin contract after the old sysadmin ceased being on speaking terms with the company owner. This made it difficult for me to learn what s going on.
6. If your network is in any way complex (IE it s something that needs some skill to manage) then it will probably be impossible to hire someone who has experience in all the areas of technology at a salary you are prepared to pay. So you should assume that whoever you hire will do some learning on the job. This isn t necessarily a problem but is something that needs to be considered. If you use some unusual hardware or software and want it to run reliably then you should have a spare system for testing so that the types of mistake which are typically made in the learning process are not made on your production network.

Conclusion If you have a business which depends on running servers on the Internet and you don t do all the things in the above list then the reliability of a service like Hetzner probably isn t going to be an issue at all.

• [1] http://www.hetzner.de/hosting/produktmatrix/rootserver-produktmatrix-ex
• [2] http://aws.amazon.com/ec2/

Related posts:

1. Servers vs Phones Hetzner have recently updated their offerings to include servers with...
2. Why Internet Access in Australia Sucks In a comment on my post about (relatively) Cheap Net...
3. The National Cost of Slow Internet Access Australia has slow Internet access when compared to other first-world...

Today I release a Python client library to query Munin servers. I wrote it as part of some experiments I did a few weeks ago. I discovered there was no client library to query a Munin server. There's PyMunin or python-munin which help developing Munin plugins, but nothing to access the munin-node and retrieve its data. So I decided to write a quick and simple one, and it's released under the name of PyMuninCli, providing the munin.client Python module.

I just uploaded new metapackages featuring dependencies of several new packages prepared thanks to the great work of the Debian Med team. Here are the newcomers (and packages we lost):

med-bio:
+ ballview
+ bowtie2
+ cd-hit
+ clustalo
+ ffindex
+ gassst
+ grinder
+ hhsuite
+ profphd-utils
+ proftmb
+ profphd
+ profphd-utils
+ pynast
+ qiime
+ r-bioc-cummerbund
+ reprof
- seq-gen (turned out to be non-free)

med-bio-dev:
+ libchado-perl
+ libffindex0-dev
+ libtfbs-perl
+ libpal-java
+ librg-reprof-bundle-perl
+ librostlab-blast0-dev
+ librostlab-blast-doc
+ librostlab3-dev
+ librostlab-doc
+ libzerg0-dev
+ libzerg-perl

med-data:
- freediams (restructuring upstream, will be back with next release hopefully)

med-imaging:
+ imagevis3d
+ itksnap
+ odin
+ volview

med-imaging-dev:
+ python-pyxnat

med-practice:
+ clinica
- freediams (restructuring upstream, will be back with next release hopefully)

Seems the regular sprints of the Debian Med team have enhanced the team (regarding the number of people and the effectivity of the cooperation). Thanks to all people who joined our effort to make Debian the best free operating system for medical care and biological research.

I previously wrote about my first experiences with BTRFS [1]. Since then I ve been using BTRFS on more systems and have had good results. The main problem I want to address is with the reliability of RAID [2]. Requirements for a File Server Now one of my clients has a need for a new fileserver. They need to reliably store terabytes of data (currently 6TB and growing) which is mostly comprised of data files in the 10MB 15MB size range. The data files will almost never be re-written and I anticiapte that the main bottleneck will be the latency of NFS and other network file sharing protocols. I would hope that saturating a GigE network when sending 10MB data files from SATA disks via NFS, AFS, or SMB wouldn t be a technical challenge. It seems that BTRFS is the way of the future. But it s still rather new and the lack of RAID-5 and RAID-6 is a serious issue when you need to store 10TB with today s technology (that would be 8*3TB disks for RAID-10 vs 5*3TB disks for RAID-5). Also the case of two disks entirely failing in a short period of time requires RAID-6 (or RAID-Z2 as the ZFS variant of RAID-6 is known). With BTRFS at it s current stage of development it seems that to recover from two disks failing you need to have BTRFS on another RAID-6 (maybe Linux software RAID-6). But for filesystems based on concepts similar to ZFS and BTRFS you want to have the filesystem run the RAID so that if a block has a filesystem hash mismatch then the correct copy can be reconstructed from parity. ZFS seems to be a lot more complex than BTRFS. While having more features is a good thing (BTRFS seems to be missing some sysadmin friendly features at this stage) complexity means that I need to learn more and test more before going live. But it seems that the built in RAID-5 and RAID-6 is the killer issue. Servers start becoming a lot more expensive if you want more than 8 disks and even going past 6 disks is a significant price point. As 3TB disks are available an 8 disk RAID-6 gives something like 18TB usable space vs 12TB on a RAID-10 and a 6 disk RAID-6 gives about 12TB vs 9TB on a RAID-10. With RAID-10 (IE BTRFS) my client couldn t use a 6 disk server such as the Dell PowerEdge T410 for $1500 as 9TB of usable storage isn t adequate and the Dell PowerEdge T610 which can support 8 disks and costs $2100 would be barely adequate for the near future with only 12TB of usable storage. Dell does sell significantly larger servers such that any of my clients needs could be covered by RAID-10, but in addition to costing more there are issues of power use and noise. When comparing a T610 and a T410 with a full set of disks the price difference is $1000 (assuming $200 per disk) which is probably worth paying to delay any future need for upgrades. Buying Disks The problem with the PowerEdge T610 server is that it uses hot-swap disks and the biggest disks available are 2TB for $586.30! 2TB*8 in RAID-6 gives 12TB of usable space for $4690.40! This compares poorly to the PowerEdge T410 which supports non-hot-swap disks so I can buy 6*3TB disks for something less than $200 each and get 12TB of usable space for $1200. If I could get hot-swap trays for Dell disks at a reasonable price then the T610 would be worth considering. But as 12TB of storage should do for at least the next 18 months it seems that the T410 is clearly the better option. Does anyone know how to get cheap disk trays for Dell servers? Implementation In mailing list discussions some people suggest using Solaris or FreeBSD for a ZFS server. ZFS was designed for and implemented on Solaris, and FreeBSD was the first port. However Solaris and FreeBSD aren t commonly used systems so it s harder to find skilled people to work with them and there is less of a guarantee that the desired software will work. Among other things it s really convenient to be able to run software for embedded Linux i386 systems on the server. The first port of ZFS to Linux was based on FUSE [3]. This allows a clean separation of ZFS code from the Linux kernel code to avoid license issues but does have some performance problems. I don t think that I will have any performance issues on this server as the data files are reasonably large, are received via an ADSL link, and which require quite a bit of CPU time to process them when they are accessed. But ZFS-FUSE doesn t seem to be particularly popular. The ZFS On Linux project provides source for a ZFS kernel module which you can compile and load [4]. As the module isn t distributed with or statically linked to the kernel the license conflict of the CDDL ZFS code and the GPL Linux kernel code is apparently solved. I ve read some positive reports from people who use this so it will be my preferred option.

• [1] http://etbe.coker.com.au/2012/02/10/starting-with-btrfs/
• [2] http://etbe.coker.com.au/2012/02/06/reliability-raid/
• [3] http://zfs-fuse.net/
• [4] http://zfsonlinux.org/

Related posts:

1. ECC RAM in a Cheap Machine In a comment on my previous post about ECC RAM...
2. Starting with BTRFS Based on my investigation of RAID reliability [1] I have...
3. Dell PowerEdge T105 Today I received a Dell PowerEDGE T105 for use by...

Fontconfig 2.9.0 uploaded to Debian Experimental Thanks to Akira Tagoh for taking over maintenance of fontconfig. As a result of this switch, there s a new release, 2.9.0. Along with this new upstream release, I ve responded to Debian bug 651493 and removed all defoma support from the fontconfig packages. Installing the new version should remove all traces of the old defoma support as well. I d love to hear from people with success (or not) in testing this version of the package; 2.9.0 should be uploaded to unstable in time for the next freeze.

So, the vote is over, and Stefano won. During many past DPL elections, I've made my vote public, and this one is no different:

V: 1223 		597c362e6156ec7e37b334837161da26

That's me, in this list. Obviously I wouldn't run if I'm not serious about it, so I voted myself first. As to the other part: I thought long and hard about that, but eventually came to the conclusion that both Stefano and Gergely had properties as a candidate that I liked, and properties that I didn't like, and that therefore I couldn't prefer either of them over the other. I found Gergely's platform to be fairly similar to my own, which is a good thing; but there were a few details that made me have some pause about his candidacy. And while I stand by the things I said during campaigning about Stefano as a DPL, the truth is that the project could be far worse off than to have him re-elected. As to the outcome... I can't say it's entirely unexpected. I knew it was a long shot even before I started, and then campaigning didn't excactly go as I would have hoped. I expected to lose, but not by such a margin what Stefano did wasn't winning, it's called 'trashing the opposition'. Congratulations, zack, for a truly exceptional performance; and thanks, also to Gergely, for being a worthy opponent. In closing, I'll say that I don't think I'll run again. I've gone through the process three times now, and have never gotten very close to winning; this probably means that what I feel about the position of DPL is somewhat removed from what the project as a whole thinks about it. So, absent some radical changes in either the project itself or in the way I look upon it, another candidacy from me is highly unlikely. I guess I'll have to find other ways to spend my time...

Unix rocks, or at least one of its design feature does: everything is a file. Here is one funny use of that feature. I consider that programs that manipulate text should basically take it on their standard input, and write it to their standard output, while specifying the name of an input or output file should be an optional refinement. Well, at least one program was designed the other way: when used to import a foreign key, ssh-keygen -i has no option to read it on its standard input. No problem, this can be worked around:

# ssh-keygen -if /dev/stdin
[paste the foreign key here]

Unfortunately, that does not work with every action of ssh-keygen since not all of them were written to be able to handle streams, which cannot be rewound.

Another weekend, another running opportunity! This was a nice, simple, fast race. The announcer was claiming (if I understood correctly) it is the fastest race around Z rich: completely flat, on an airfield (which unfortunately meant all paved road). The weather was perfect (for running), a bit cold but no problems with overheating. So I managed my fastest time ever: according to the my Garmin (which for the first time recorded a slightly longer distance than the official one), I managed to run 10.18km in 50:39, which makes it 4:58/km! For the first time, below the 5:00 mark, yay! I'll ignore the official marking which claimed 10km in 50:57, since that ruins my nice result, hah! Back to earth however let's see some stats about this race. Just to put it in context: My current running speed is lower than the winner in the 70+ age category by a significant amount. Based on the graph shape, I would probably win at the 85+ category . Or to put it in a slightly different context, a cultural one. Back in my home country (Romania), a 70-year old person (especially male!) that is still able to move around well and to manage by himself is (most of the time) an exception. Of course there are many old men who are doing well, but in general old people are (usually) considered deprecated by this age. In comparison, in Switzerland, they are still active and are doing sport. And some of them, as you can see, doing it quite well. The difference between these two cultures in this regard (sport) is huge. Doing sports (except playing football) is considered something unusual, and in my home town there's a somewhat linear relation between people's age and their weight (both are monotonically increasing). When I first came to Switzerland, I was shocked to see so many people over 50 that are fit and active. Now, every time I go back to Romania, I'm shocked to see people so many people overweight and looking more than their actual age. I can't help but wonder what is the cause of this disregard for health or aversion to sports. Just the fact that "it's expected" for older people to be unhealthy? Is it somehow related to the difference in income/standard of life (I can't see a trivial connection)? Is it to lack of education about how to live a healthy life? Or maybe it's not a country difference, but rather the fact that I grew up in a quite small town; people in Bucharest are indeed looking more after their health than in my home town, and are therefore fitter. Who knows Anyway, rant over, and I'm still happy that I managed to beat my own record, thanks to a flat race and favourable weather!