On a slow line (like mine, @56k) even updating pbuilder could be a problem (or a really boring task):

[host]$ sudo pbuilder update
[...]                                                      
Get:4 http://debian.fastweb.it unstable/main Packages [5302kB]

5Mb are enough to do this trick (NOTE: it will work only if you machine and the pbuilder use the same mirror). First, update your box apt packages list with

[host]# apt-get update

once done, you'll find in /var/lib/apt/lists/ the packages list we need. Let's copy those files in a new location:

[host]# cp -arp /var/lib/apt/lists/ /tmp/

then, login into the pbulder chroot with:

[host]$ sudo pbuilder --login --bindmounts /tmp/lists/ --save-after-login

(/tmp/lists/ will be mounted inside the chroot with the files we've just copied, and --save-after-login will save our changes once done). Now

[chroot]# cp /tmp/lists/*astwe* /var/lib/apt/lists/

to copy the lists for Fastweb mirror only (the one I'm using), now

[chroot]# apt-get update
Get:1 http://debian.fastweb.it unstable Release.gpg [189B]
Get:2 http://debian.fastweb.it unstable Release [86.4kB]
Get:3 http://debian.fastweb.it unstable/main Packages/DiffIndex [2038B]                                                       
Fetched 88.7kB in 12s (6962B/s)                                                                                               
Reading package lists... Done
[chroot]#

now only few files are downloaded.

I used this trick earlier, in cases where creating or updating the apt packages list for pbuilder was a problem, since the files always resulted corrupted.

England swings like a pendulum do! There's another fuel price protest and the coverage in the London press is pretty biased, with occasional balanced reports and very rare dissenting opinion. One of the favourite whines on news-and-nutters phone-ins is "waah, I live in a village, I need my car". While that's true for some people, most villagers could switch to bicycles for many journeys without problems. At the moment, the biggest problem with cycling to town is the number of cars on the small lanes, followed by the number of potholes. Switching to cycling or walking will have a triple benefit: fewer cars on the road will free up space for cycling, wear the roads out less and reduce fuel demand (so petrol should become cheaper for those who really need it). Over the last few days, I've been happy to read Bike The Drive 2008 [Dirk Eddelbuettel], Mountainbike, By Joerg Jaspert and How to Start Bicycling to Work, by John Goerzen. A couple of tweaks to that last one: in England, I don't think that a cycling helmet is necessary. I've not worn one for the last few months (it went mouldy after a rain storm) - I find I can hear traffic better and many drivers seem to give me more room on the road. I wonder if helmet-wearing "dehumanises" cyclists to drivers? The safety data seems rather confused, but it's a personal choice. If you feel safer with a helmet, wear one. I also wear ordinary business or casual clothes, relying on a good quality commuter saddle rather than cycling shorts. I suspect that drivers here are developing a sort of blindness to the "screaming yellow" hi-vis jackets, so I don't wear those - but sometimes I wear hi-vis reflective armbands if I'm wearing black in the dark. I agree completely with the comments on that page about being predictable, Cateye lights and pannier bags. Finally, Bike Week 2008 starts on 14 June, which would be an ideal time to try a group ride - or just get a free breakfast for cycling into town.

John Goerzen reminds me of what from my perspective is one of the most amusing parts of watching the Democrats squabble over whether estrogen or melanin is more important in a presidential candidate. Apparently, the same people who just a few short months ago were the progressive vanguard of the peoples struggle to speak truth to the fascist power of Bushitlerburton are, in fact, STUPID EVIL RACISTS!1!!! Of course on August 25, they will magically turn back into audacious hope changers but until then I LOL.

Michelle’s post‡ today on laptops in the classroom (in a similar vein to this article I read last month on the suggestion of Glenn Reynolds) reminded me that I had a few items from the past few weeks still in my Google Reader queue of “things to blog about” related to Margaret Soltan’s continuing crusade against the use of PowerPoint* and its ilk, and specifically Timothy Burke’s partial rebuttal:

What’s the difference between bad usage of PowerPoint in lectures and bad lectures that involve hand-outs, overhead transparencies and writing on the chalkboard? Are we just complaining about old wine in new bottles here? Is the real culprit professorial droning at classrooms of 200+ students followed by recite-repeat-and-forget examinations? I think it’s at least plausible that the technology is just giving us a new reason to pay attention to a pedagogy whose effectiveness has been suspect for two generations.

I dare say I’m among the last doctoral students who was “trained”—and I use that word loosely—to teach prior to the widespread use of PowerPoint. Four years of full-time in-classroom experience, mostly with small lectures and seminars, has brought me basically to agreement with Burke on this point—complaints about PowerPoint essentially boil down to complaints about either instructional laziness or the whole nature of lecturing, or as a Burke commenter puts it, ”[e]xactly how does one teach even 80† students at once without succumbing to passive data transfer?” The non-use of PowerPoint or some other form of instructional technology seems to me to be a luxury confined to those who only teach small seminars and graduate students, and while my personal career aspirations lean in that direction the reality is that I’m several years away (in terms of research productivity) from being there—if I ever get there. Burke in his comments hits the nail on the head, I think, when it comes to any sort of visual presentation in class:

It seems to me that the absolutely key thing is to avoid speaking the slides literally. They’re best as definitions, key concepts, images: the kind of thing you’d stop your flow of lecturing to write on the chalkboard. They’re not the lecture itself.

I think there are three useful aspects to a lecture: what you put on the board (or slides), what you say, and the general outline. If you’re preparing a handout or something to stick on Blackboard for students, the outline or outline-plus-slides is what they need, along with space to fill in the gaps. An alternative approach is to make the slides/board material the outline; several of the more effective teachers I had (my high school history teacher and a political science professor at Rose-Hulman) took that approach. But you can’t shovel your script into PowerPoint and expect that to work well, any more than you’d expect that writing it up on the board, or for that matter reading a paper verbatim at a conference would be a good presentation, to work. All this discussion leaves aside the question of teaching anything that involves symbols (chemistry, mathematics, statistics) which I think requires a different approach than bullet-points. In class, mathematics and statistics (and, by extension, social science research methods courses) lend themselves to a combination of “passive” PowerPoint-style presentation and more spontaneous problem-solving and brainstorming; for example, one of my early activities is to have the class try to operationalize (define in terms of a measurable quantity or quality) a concept like “globalization,” which you can’t really do with a static slideshow even though you can define terms like “operationalization” that way. Similarly, while you can step through the process of solving a problem in a slideshow I think it’s more effective to demonstrate how to step through the process on the board. Unfortunately, many classrooms aren’t set up to allow you to present and use a board simultaneously; some of TAMIU‘s lecture halls have a nice design where the projection screen is above the board, so you can write on the board without having to do anything special with the slideshow, but rooms most places are designed for “either-or” which can be a real pain—fiddle with the control system to blank the screen, raise the screen, write on the board, then lower the screen, switch the screen back on. After a few iterations of that in a single class, you’ll never do it again. I freely admit I haven’t figured everything out yet; my current methods slides are pretty good lecture notes but pretty rotten for projection. One of my projects for this summer (postponed from last summer after I learned I wouldn’t be teaching any methods courses this year) is to work on my research methods lectures to incorporate advice from Andrew Gelman’s book so I can lay the groundwork for my plot to take over the world effort to produce a workable, but rigorous, methods curriculum at both the undergraduate and master’s levels for political science, sociology, and (at the grad level) public administration. More on this theme from Laura at 11D, who takes note of some of the more positive technological developments associated with academe. And, another of Burke’s commenters links this hilarious example of what not to do with your slides.

* I use “PowerPoint” as shorthand for the use of a computer-projector based slideshow-style sequential presentation of items associated with a lecture, a technique obviously made famous by the Microsoft software package but also available with many other software packages such as Apple’s Keynote, OpenOffice.org Impress, and several PDF viewers including Adobe Reader, xpdf, and GNOME‘s Evince.
† I’d put the cutoff significantly lower, at around 30–40 students. Beyond that point, one might as well just blow the cap off the class.
‡ By the way, it’s nice to see Michelle’s blog back from haïtus! (Where else would I keep up with current Mexican politics?)

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Update Added screenshots

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I spend a lot of time working in front of a screen (many hours in a dimly lit room) and eye fatigue is an issue. A consistent color scheme, especially one which is easy on the eyes, is important and it also helps to have way of doing that where the directives are not all scattered all over my Emacs-lisp setup. Enter Emacs Color Themes, available as the Debian package emacs-goodies. Aided with a HSL color picker, I set around trying to create a dark color theme for Emacs. It does not help that I am blue-green color blind, so subtle variations are often lost on me. I do want to use color contrast to increase productivity, but I also want to avoid the jarring angry fruit salad look, and so I am in the process of crafting a logical color scheme that is high contrast enough for me, without being too unpleasing. In circumstances where there a lot of related faces that can be viewed, for example, the Gnus group buffer, consistent and logical color choices are the only sane option. Gnus groups can be news (bluish) or mail (greenish), have states (large number of unread messages, normal, and empty). The large number unread groups have highest luminosity (appear brighter), and the empty one have lower luminosity (appear greyer), but have the same hue and saturation. Sub states and group priorities are rendered using a color series which has constant luminosity and saturation, and vary in hue by a constant separation so all the related groups have the same brightness ( mail,news / unread,normal,empty ), and a graded selection of foreground colors. It sounds more complicated that it looks. The eye is drawn naturally to the unread groups, and first to the mail, then USENET groups (which is my preference). Similar color variations occur for individual messages in a group; high scoring messages bubble to the top, and have a higher luminosity. This color schema has made me slightly faster at reading mail/USENET. In the message itself, quoted mail messages from different people are color coordinated, with high contrast between citations that are close to each other in the hierarchy, so it is less likely that one misunderstands who said what in a long conversation. The resulting scheme covers programming languages, Gnus, Erc, mail, org-mode, CUA-mode, apt-utils, bbdb, compilation buffers, changelog mode, diff and ediff, eshell, and more. This has allowed me to consolidate all my color directives into a single file, and is in a format that might be usable by others. See the wiki page for details about how to use and switch color themes in Emacs. Enjoy.

Yesterday, I wrote about bicycling to work, pointing out that it's a safe, inexpensive, way for many people (including office workers without access to showers) to get to work. There were a lot of thoughtful comments there too.

Today I'd like to provide some tips for getting started commuting on a bicycle. As I'm just getting started on this, these are mainly things I've learned from poking around online, so I'll be including lots of links.

The Bicycle

This varies from person to person, but as a general rule: if you have a very short ride -- say a mile or less -- you can probably just use any old bike and a bicycling helmet. Don't try to use a motorcycle helmet. It won't vent your head, so you could overheat. Also, it won't be comfortable.

Most people will have a longer ride and will want to get a bike that works specifically for them. Each model of bicycle comes in different frame sizes. It's important to get a bicycle that is the right size for you. Also, you'll want to get a quality bicycle that will let you be fast and won't break down along the way.

For all these reasons, I -- and every single other person I've ever seen talk about this -- highly recommend that you buy your bicycle from a bicycle shop. Don't buy a bicycle from a "big box" store like Walmart or Target. They may be cheaper up front, but you'll pay for it in the long run because they won't last as long, won't fit you as well, and may even be unsafe. Bike shop staff will help you find a bike that fits you, which is important for avoiding aches and pains and even injury. They'll be able to help you find appropriate accessories for your bike, as well as repair it. Here is a helpful article on this topic, written by a bike shop.

Generally speaking, bike shops can repair bikes bought at any other bike shops. However, they can instantly recognize bikes bought at big box stores. Many will repair those too, but some refuse to work on some of those bikes on the grounds that it is impossible to bring them to the level of service they expect their mechanics to do.

Aches and Pains

With any sport, when you start it, you can expect a little bit of aches and pains at first, as you start using muscles that you may not have really used at first. Bicycling is no exception, but it's easy to deal with.

Your first stop if you have aches and pains might be the where does it hurt page. It provides detailed, helpful advice. There are also some common things that go wrong for people.

First on the list is wrong size of bike or improper adjustment of your bike. You want a bike frame that is the right size for you, and you want the seat and handlebars adjusted properly for you. A bike shop can help you get this done easily. If your feet can reach the ground while you're on the seat, you almost certainly have the seat too low, which is a common mistake.

Sometimes the way you position yourself on the bike, or your technique, could be to blame.

Also, clothing can be a problem. A good place to start here is with some cycling shorts. Another common complaint from new cyclists appears to be blisters on the feet. This can be caused by improper positioning on the pedals, or by using the wrong type of sock. Typical socks absorb moisture and trap it next to the skin; bicycling socks will wick it away and let it evaporate. In fact, cycling clothes: socks, shorts, and jerseys (shirts) are all designed to wick moisture away from you and let it evaporate, which keeps you cooler and more comfortable. Bicycling gloves are cheap and can help your hands stay comfortable.

Expense

You can easily save thousands of dollars by riding a bicycle instead of driving a car. Bicycles do need periodic maintenance, just like a car. Usually you can do a lot of that yourself. It probably will pay off to take your bike in to the shop for an annual tuneup. If you have no bicycling equipment at all, and buy your equipment at a bike shop new, you can probably get started for around $500. Even that will probably pay for itself in less than a year if you average riding your bike at least a few times a week.

Safety

Safety on a bicycle can usually be summed up with three rules: be visible, be predictable, and ride with traffic.

Unless there are dedicated bicycle-only lanes or paths, the safest way (in the United States) to ride your bike is on the road, riding with traffic (acting like a car). Don't ride on a sidewalk, and never ride against traffic. This may sound counter-intuitive, but it is backed up by solid research. It all has to do with being predictable. Nobody is looking for something the speed of a bicycle to emerge from a sidewalk to cross a road or driveway. Sidewalks often aren't that visible and frequently don't provide enough room to pass. Sidewalk-riding cyclists get into accidents all the time with cars backing pulling out of driveways, making turns, or even just driving down a road where the cyclist cuts in front of them to cross a street.

A great book for learning how to ride in traffic can be viewed free online: the Bicycling Street Smarts book. There are also some safety videos online that are helpful.

Staying visible is certainly important. In some places, like cities where cyclists are common, drivers are going to be on the lookout for you already. In my case, I'm riding on rural roads that have some hills, where cyclists are rare, so I'm putting extra effort into this.

Staying visible in the day or at night starts with high-visibility clothing. A "screaming yellow" jersey or an ANSI safety reflective vest (less than $10) are good ways to do that. Several people recommend a Cateye TL-LD1100 flashing tail light for use at night, or even for daytime use when visibility is critical (such as my situation). If you will ever ride at night, laws require you to have the proper reflectors on your bike. And, you must also have a white headlight that does not cover up your front reflector (in some locations, you may also be required to have a red tail light that doesn't cover up your reflector). Companies like Cateye carry those products as well.

Other tips: avoid drainage covers; they sometimes have slats that a bicycle tire could fall into.

Accessories

Here are some suggestions you might consider as a commuter.

Start with pannier bags. They mount over your rear tire and are cooler for you than a backpack because your back can still breathe. They're more aerodynamic than a front basket. You can get bags suitable for carrying papers, laptops, a change of clothes, etc.

Next on your list might be a bicycle lock, to help keep it from being stolen. Your local bike shop can make suggestions here.

You might want to consider a spare inner tube (about $5) and tire-changing tools (also about $5) to carry with you in your bag. You wouldn't want to have to walk 5 miles if you get a flat.

Along with that goes an air pump. I suggest a frame pump -- it's a small pump that can clip on to your bicycle's frame, so you always have it handy. Obviously you will need this if you have to change a tube, but it could be handy even if you don't.

You can find some more suggestions from bicycling.about.com and from Mike or your local bike shop.

Where to buy

Besides your local bike shop, you can buy a lot of accessories online. I wouldn't suggest buying a bicycle online, because you really want to get a good fit at a bike shop.

When I asked at bikeforums.net, readers suggested three online stores:

www.pricepoint.com
www.bikenashbar.com
www.performancebike.com

You can also find some bicycling accessories at general-purpose stores like Amazon or sporting goods stores like REI. I personally wouldn't recommend local "big box" sporting goods stores any more than I would Walmart or Target for this stuff, though.

More info

For more information, check out my bicycling links at del.icio.us.

Hi all!

This is my first post on Planet!

I'm an italian guy working in Debian since a couple of years (but I'm a user since 5 years).

I maintain some packages (and I'm a DM), and I'm particular active in Python stuff (you can find me often on #debian-python@OFTC).

I'm in the NM queue (P&P1 passed, waiting for a reply on P&P2 :D ).

You'll hear back from me soon!

To continue the CECB mini-review series, I picked up an LG/Zenith DTT900 at Circuit City in Southaven this evening with one of my two digital converter box coupons (and $24ish of my hard-earned money at Sam’s Town’s blackjack tables). With essentially the same setup and conditions (same television and el-cheapo VHF/UHF indoor antenna) as the RCA DTA800B tested before, the initial channel scan found the same 17 channels/sub-channels. However, the Zenith’s ability to manually add channels meant that I was able to add WMC-DT/NBC 5 (RF channel 52) and with some fiddling get a reasonably stable signal, something I was unable to accomplish with the RCA—this isn’t that surprising, since the Zenith is based on LG’s ATSC digital tuner chipset, which is known for its superior reception capabilities over most other silicon. In addition, other channels (WHBQ-DT/Fox 13, WPTY-DT/ABC 24, and WLMT-DT/CW 30) that were less-than-stable with the RCA were rock-solid with the Zenith. Bear in mind that WMC is running on a different frequency (and lower on its tower) than it will after the transition is complete in nine months, so indoor antennas in Shelby County at least should cope better with WMC when it is back on VHF channel 5. The built-in guide is a little weaker than that included on the RCA model; the Zenith’s only shows program data for one channel at a time. The Zenith, however, has more functionality accessible from the remote control, including a “favorite channels” feature that would be useful for the compulsive surfer who isn’t interested in switching past the news and weather loops on 3–2 and 5–3 when doing the Letterman/Leno (or Conan/Craig) shuffle, and a sleep button. I also thought the Zenith’s menus were a little more polished and better organized. On the antenna front, the Zenith, unlike the RCA, does not provide an attachment for digitally-steered “SmartAntennas,” which may be a consideration if you already have one of these (they are apparently uncommon at present) or have hard-to-tune channels in multiple directions which might benefit from this high-tech solution. The Zenith’s better signal-handling may reduce the need for a fancy antenna, however; either way, you should probably check out TVFool’s antenna aiming guide or the somewhat less-friendly CEA/NAB-sponsored AntennaWeb website to determine what sort of antenna solution is going to be necessary for you before spending money on one. The only real problem I encountered in testing was that the “zoom” setting seemed to behave oddly; at first, letting it decide on its own seemed to work OK on some channels, but then I ended up with some bizarre “squeezed” pictures on several HD channels. Expect to manually fiddle with the zoom setting when channels switch between showing native 16:9 and pillarboxed 4:3 programs. Those who use closed captioning will also find that it seems to forget the CC setting when you switch channels, although I think there’s a menu option to leave closed captioning on all the time. Finally, caveat emptor: many manufacturing runs of this converter, and its near twin sold by Best Buy under its Insignia house brand, apparently have an audio problem that certain TVs seem to be more susceptible to than others. The converter I purchased had a manufacturing date of April 2008, which has been reported to be the run in which this problem was fixed, and I observed no audio problems during my testing (on an admittedly low-end CRT stereo television/VCR over RCA cables). Overall, I’d assess the LG/Zenith DTT900 as a better option for those who are planning to use the converter on a regular basis; however, if you’re simply buying a converter to serve as a “lifeline” when cable or satellite television is disrupted, or if you would like to take advantage of the SmartAntenna connectivity on that unit, the RCA model is probably adequate for most needs and seems to retail for about $10 less.

Last week-end, I was in Prague for FOSSCAMP, a Canonical-sponsor event aiming at bringing together people from various Free Software projects. Such an event is a very good idea, especially after the openssl debacle, where we saw how difficult it is to build good relationships with other Free Software projects. The event was organized in a rather interesting way: the attendees make up the schedule as the event happens, by adding sessions to the timetable using marker pens on a whiteboard (see picture, hi Jorge!). If we have a spare BOF room at Debconf, it would be great to do the same thing: I always find it frustrating that many important discussions at Debconf happen outside BOFs/lectures, and are so easy to miss, simply because you submit talk proposals months before Debconf, so you can’t know yet what will be the hot stuff when Debconf finally arrives :-) It was also interesting to see all the different ways people organized BOFs. It might be interesting to write a list of DOes and DON’T about BOFs (not that the sessions weren’t of good quality!). Does anyone know if such a list already exist? And finally, as usual, it was great to meet all those people from this nice community again. If you still believe that some projects are fighting with each other, you need to attend such an event. And special thanks go to Ond ej ert k for guiding me through a visit of Prague!

Matt Bottrell has written about some issues related to the acceptable weight of laptops for school use [1]. Matt cites a reference from the Victorian government stating that a school bag should not be heavier than 10% of the body weight of the child who carries it [2]. So the next thing we need to do is to calculate what a student can carry without being at risk of spinal injuries. Firstly we need to determine what children weigh, if we restrict this to the 14+ age range (the older children have more need of computers) then children are almost as heavy as they will be when they are 18 and can carry significantly heavier bags than those in the 10+ age range. Also it seems reasonable to consider the 25th percentile weight (the weight which is exceeded by 75% of children). Of course this means that 25% would be carrying overly heavy bags but it does give us a bit more weight allowance. The 25th percentile weight for white girls in the US is 48Kg [3]. The 25th percentile weight for white boys in the US is also 48Kg [4]. When considering the Australian situation it seems that white children in the US will be most similar (in terms of genetics and diet). The 25th percentile weights at age 18 are 53Kg for girls and 64Kg for boys. So the acceptable bag weights would be 4.8Kg for 14yos, 5.3Kg for 18yo girls, and 6.4Kg for 18yo boys. The next step is to determine the weight carried to school. The weight of one of my laptop bags is almost 1Kg, I think that a school-bag would have a similar weight. When I was at school I recall that the worst days for carrying baggage were when I had PE (Physical Education - sports), the weight of PE gear was a significant portion of the overall weight I carried. I tried to estimate this by weighing a track-suit top, a t-shirt, and a pair of board-shorts (the only shorts I could find at short notice), and it was almost 1Kg. While the board-shorts might weigh more than PE uniform shorts I didn’t include the weight of track-suit pants. Assuming that a female PE uniform has the same weight as a male uniform is the least of my assumptions. The weight of a good pair of sneakers (suitable for playing basketball and other school sports) that is in my size is just over 1Kg. To get a rough estimate of the weight of lunch I put six slices of bread and a small apple in a lunch box and found that it weighed 500g. A real lunch would probably include four slices of bread but the other things would weigh at least as much as the extra two slices. If a drink was included then it could be more than 500g. So the total is 3.5Kg for bare essentials (including PE gear) without including any books! It seems that it would be impossible to stick to the government recommendations for school bag weight if a full set of PE gear is included. Probably the best thing that could be done would be to make a school uniform allow wearing sneakers which removes 1Kg from the overall bag weight. So a bag with lunch and PE gear (minus sneakers) is about 2.5Kg, leaving 2.3Kg for books etc at age 14. As text books for 14yo children are considerably thinner than those for 18yo children, it seems that this might be achievable. Fitting a couple of text books and an EeePC into the 2.3Kg weight budget should be achievable. But fitting a full size laptop (which seems to start at about 1.8Kg) and some text books into a 2.3Kg budget will be a challenge - it might be possible to do that but wouldn’t leave any budget for the random junk that children tend to carry around. For an 18yo girl, the weight budget (after the basics have been deducted) is 2.8Kg, it seems likely that on occasion the weight of year-12 text books will exceed that. Therefore it seems that the only way of avoiding spinal injuries in year-12 girls would be to have text books stored in digital form on a light laptop such as an EeePC. Rather than avoiding the use of laptops because of weight (as some people suggest), laptops with electronic text books should be used to replace traditional text books! An EeePC weighing less than 1Kg will give a significant amount of extra capacity for any other things that need to be carried. If there is little other stuff to be carried then 75% of 18yo girls should be able to carry a full size laptop plus PE gear without risk of back injuries. If digital text books are used then if in any journey two text books (which according to my previous measurements can be as much as 1.6Kg [5]) can be replaced with an EeePC then overall something like 600g is saved (depending on the configuration of the EeePC, if one battery was stored at home and another at school then it could save more than that). It seems that a year 12 girl who has PE and three science subjects scheduled on the same day would be most likely to exceed the recommended weight in the current situation (even without having to carry a spare pair of shoes), and that carrying a laptop with digital text books would be the only way of avoiding back injury. For an 18yo boy the weight budget is 3.9Kg after the basics have been deducted. So if they don’t carry other random stuff in their bag (I probably had 1Kg of random junk in my bag on occasion) then they could carry PE gear, a full sized laptop, AND a full set of text books. It seems to me that there is no situation where children would be unable to have a laptop within the reasonable weight allowance if digital text books were used. The only way that the weight of a laptop could be a problem would be if it was carried in addition to all the text books. One final point, it would be good if books from the Gutenberg project were used for studying English literature, that’s one easy way of reducing weight (and cost). Also it would be good if there was an option for a non-literature based English subject. Knowledge of English literature is of no value to most students. It would be better to teach students how to write while using topics that interest them. Maybe have blogging as an English project. ;)

• [1] http://matt.bottrell.com.au/archives/155-Laptop-clarifications.html


• [2] http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Back_pain_schoolbags?open


• [3] http://www.halls.md/on/girls-weight-w.htm


• [4] http://www.halls.md/chart/boys-weight-w.htm


• [5] http://etbe.coker.com.au/2008/02/18/laptop-vs-book-weight/

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foosel tagged me, whatever that means. Perhaps it’s the English word for “Stöckchen” (German for “small stick”) of which I always wondered how the English blogging part of the blogosphere is calling that kind of coercing blog posts… ;-) So these are the rules:

1. blog a list with your favorite desktop Linux software (as many or few you want)
2. add links to the software project’s websites
3. post these rules
4. tag three other Linux using bloggers

Interestingly splitbrain, who started the thing just calls it “Meme”, but to me memes are the same thing just without duress. ;-) So you want to know about what Linux desktop software I like and use, hmm? Desktop means GUI, doesn’t it? There are only a few GUI application I really use often since, as you probably know, X is primarily a terminal multiplexer and screen resolutions are compared by how many 80×25 xterms with fixed font you can get on one screen without overlapping. ;-) But to be honest: Although I’m more the command line guy hacking cryptic lines into windows with small fonts, there are a few thing where I don’t want to miss X and the GUI applications: For all things web – that means web browser, feed reader, etc. But then there is also a bunch of GUI software I use occasionally or as alternative tool to some text mode or command line software. Web

• Liferea – My favuorite feed reader although it takes ages to start and since a few days also starts crashing, probably since I have configured it to cache up to 1000 items per feed and have subscribed to several hundred feeds. I do not read them all though, but I use them togther with Liferea’s “search all feeds” feature as a Google News replacement. ;-) I though read a lot of feeds in it, since I use it for news, blogs, webcomics and to read missed tweets on Twitter. It organizes the feeds in a tree structure so I can easily group different types of content together.
• Opera – I’m back using Opera as my primary web browser since they offer alpha versions for 64-bit Linux. Initally I started using Opera with version 3.60 on Windows 95 somewhere about 10 years ago and I’ve always come back to it when no current free browser fits my needs. Although it hasn’t an AddOn possibility as Firefox has, I still prefer it over the bloaty and leaky and quite unstable Firefox 2, since it offers nearly every functionality I need (mainly mouse gestures and a flexible tab management), is fast, needs less RAM and is quite stable for an alpha version. And Firefox only offers those features I need via Addons which are often the cause for leaking or crashing. Haven’t tested Firefox 3 yet, but it’s said to be be less bloaty…
• Kazehakase – Formerly I used kazehakase as my primary web browser since I really like its user interface, but the version in Etch is quite slow and seems to have memory leaks. It’s currently the second browser I have always open. But since my browsers always have uptimes in terms of months I don’t need web browsers that are leaking, so I’m thinking about replacing it with something more stable.
• Conkeror – A Gecko 1.9 (i.e. Firefox 3) based web browser completely controllable with the keyboard. And the key bindings are those from Emacs and partially also from the classic text-mode browser Lynx. Will be available in Debian Experimental soon.
• Netsurf looks very promising as it’s a simple and fast browser with it’s own rendering engine and originating on RISC OS. But since I’m a heavy tab user (60 tabs in one window are not really seldom), a browser (yet) without tabs isn’t really that useful for me. But I hope it will get tabs soon.
• Midori – The other upcoming new browser in the Linux world is using Apple’s WebKit (which itself is based on KDE’s KHTML) underneath. Only in Experimental yet (form a Debian point of view :-). Use it on my Debian Sid machine to play around with it.
• Twitux – A simple GTK Twitter client which doesn’t clutter the screen with unnecessary icons or buttons. Just a small menu bar, status bar and the tweets.
• Azureus – In the seldom case where I need to download files via Bittorrent I either use Opera’s builtin client or Azureus. The nice thing about Azureus is that you can get nice graphical as well as textual statistics about all aspects of your downloads.

X / Desktop Environment

• FVWM – My favourite window manager for normal, big or multiple screens. I use it since more than 10 years (twm and tvtwm were its predecessors) and its configuration has evolved since then quite a bit to tinted transparent window frames and title bars, etc. I tried other window managers in between (e.g. Sawfish and GNOME’s own Metacity, each for a month or so and both together GNOME, also played around with KDE on one machine) and I always came back to FVWM. No other window manager is so fast and configurable in regards of keybindings. Handles multiple screen very well and out of the box, too.
• ratpoison – My favourite window manager for small screens (less than about 1024×768, e.g. on my EeePC, on the 8” touchscreen connected to my MicroClient Jr. or on my 1996 ThinkPad 760ED with 133 MHz Pentium 1) since it doesn’t waste screen space for window borders or title bars. It just maximizes all windows by default to screen resolution. You then can manage (split, resize, switch, close, kill) windows as you are used to manage shells and text-mode applications with screen(1). Doesn’t work that well with multiple xrandr managed screens though if they don’t have the same size.
• FLWM – The Fast and Light Window Manager. My favourite low-end but still DAU compatible window manager. Use that on demo and guest accounts, especially on low end machines.
• Synergy – connects displays of other computers (not only X but also even Mac or Windows) with your mouse and keyboard similar to a KVM switch. I use it at work to add my laptop as fourth monitor. ;-)
• trayer – A desktop environmen independend system tray developed by the FVWM Crystal Project. Since I changed from manually editing /etc/network/interface on my laptop each time I came into a new wireless LAN to using GNOME’s Network Manager, I needed a system tray for the nm-applet. Trayer is quite easy to configure using command line options and can handle tinted transparency as I use with FVWM and ATerms. So it fits in perfectly.
• ratmenu and dmenu – For showing generated menus together with ratpoison, I use ratmenu (e.g. as replacement for ratpoison’s non-interactive window list) and dmenu (e.g. as application menu using my own wrapper which generates the menu from some config file). Probably will publish that code once it proved itself stable.

xtrlock – the simplest tool to lock you desktop: The mouse turns into a lock and it only goes away if you enter the right password. No screen saver included though and everyone can see what’s on your desk. I like it though. Use it on low-end machines.

XScreenSaver and Really Slick Screensavers (GLX Port) – Configurable and command controllable screen saver daemon. Favourite modes: GLMatrix and Substrate from XScreenSaver and Lattice Sky Rocket and Hufo’s Smoke from RSS GLX.

xosview – my favourite system monitor since more than a decade.

Terminals

• xterm – there is no better X terminal emulator than the original xterm. I found no other terminal which is so fast, has no problems with text-mode applications (aterms break aptitude’s display), no problems with character set encodings, which can be embedded into other applications and which has a fully working classic Unix cut & paste.
• aterm – When I need a fancy transparent terminal for showing a fancy desktop, I use the AfterStep Terminal Emulator aterm. In that case, the system tray, the window borders, the window’s title bar and the terminal on my desktop have the same fancy tinted transparency.
• yeahconsole – A wrapper around xterm which works like the pulldown console in quake. Good for the short shell usage inbetween. ;-) The other similar pull down consoles I know (KDEish yakuake and GNOMEish tilda) had some issues with focus and keybindings while yeahconsole works just out of the box and showed no problems until now.

Audio and Video

• XMMS and Audacious – If I want to play a single list of files of the same file format or single stream, I usually use the command line tools mpg123 and ogg123. But if I need anything more fancy or more flexible, I prefer the WinAMP clones. Formerly XMMS, nowadays Audacious. Both with some old skin which I use since more than a decade and which I initially used with WinAMP 2 on Windows 95.
• mplayer – no fancy GUI, easily controllable with the keyboard, plays most video file formats I can remember. ;-)

Editing and Developing

• GNU Emacs – I’ve been raised with GNU Emacs and Lisp at university, so I’m quite sticked to that. I usually only start one Emacs instance and connect to it using emacsclient. I also like TRAMP for editing remote files. but I don’t need it that often. On machines, where I don’t want a full blown Emacs installation or under root I prefer GNU Emacs’ little brother GNU Zile (Zile Is a Lossy Emacs), but that’s text-mode and no GUI software.
• OpenOffice.org – I think it’s a really great software, but I use it quite seldom, usually only when I have to open some file in a Microsoft file format. For writing letters, articles, presentations and so I have LaTeX.
• Gnumeric – My preferred spreadsheet application. Although for some purposes I use the OpenOffice.org spreadsheet, usually when Gnumeric has not all necessary features.

Graphics

• xv – Yet another tool I use since more than a decade: No other image viewer is so fast and yet so easy to use with both keyboard and mouse. Open source, but unfortunately not (yet?) free software.
• keyjnote – fancy PDF presenter with a lot of interactive features.
• pdfcube – PDF presenter turning pages as a cube as compiz or Macs do with the desktop.

Chat

• Pidgin – I usually use irssi inside a screen for IRC as well as Jabber and ICQ (via Bitlbee), but I also often have a local Jabber client running which then is Pidgin (formerly known as GAIM).

Other Tools

• Unison – I use it to synchonise the cache and state of my feed reader between laptop and workstation. And I do indeed prefer the GUI version over the text-mode version. I use the text-mode only if I use it from some remote location.
• XKeyCaps – The ideal tool to wreck you keyboard layout. ;-)
• XGnokii – Used it to backup my former Nokia mobile phones, the 6130, the 6210i and the 6310i. Doesn’t work anymore with my new E51, though.
• Sunbird / Iceowl – Not really using it yet, but I plan to use it as my primary calendar tool.
• QEMU / KVM / KQEMU – My favourite desktop hardware emulator. (For servers, I prefer Xen for virtualization.)

Games

• ScummVM
• Planet Penguin Racer / Extreme Tux Racer (all forks of Tux Racer)
• Frozen Bubble
• Battle for Wesnoth
• cuyo, xpuyopuyo, flobopuyo
• Sauerbraten
• PrBoom / Freedoom
• Neverball / Neverputt
• Briquolo
• xfrisk
• Icebreaker
• XBomb

Non-Desktop Applications In case someone wonders about my mail client, Jabber client, IRC client, ICQ client, file manager, notes taking application, shell and versioning system – they’re all command line or text-mode applications:

• E-Mail: mutt
• Chat, Instant Messaging: irssi + Bitlbee + GNU Screen
• File management: coreutils (and sometimes busybox ;-)
• Notes: hnb
• Shell: zsh
• Version control: Subversion (svn), Mercurial (hg)

Who’s next? That’s difficult:

• maol would be interesting, but since a while he just blogs in Jeopardy style, so he would need pack all those programs into the subject of his blog post… No, not a good idea.
• Venty! No, has no active blog anymore.
• Dieter! No, no Linux user.

Hmmm, I think I have to look in a different corner of my circle of friends. Hmm. Ah, now I know:

• dyfa – not really a Linux user, but I guess FreeBSD is ok, too. :-)
• nion – this will be really interesting. He even uses more strange software than I do. ;-)
• alphascorpii – no idea what she prefers (except that it will be available as Debian package ;-)

And no, I don’t expect posts as comprehensive as mine. :-)

Last week I noticed, that Kabel Deutschland, a cable provider in germany, returns for any non existing hosts “204.9.89.60″. It seems, thats it is rolled out since last fall. Even for DNSSEC enabled infrastructure it breaks it totally:

; <<>> DiG 9.3.4 <<>> +dnssec web.pixaco.se @83.169.184.161
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; ANSWER SECTION:
web.pixaco.se. 0 IN A 204.9.89.60 Beside that, this behavour breaks the whole DNS, since many mechanism rely on a negative answer. The most visible effect for the users is, that when having a typo on surfing, he will forwarded to http://suche.kabeldeutschland.de/de.kde.assist/?domain=<domainyoutypedinyourprompt>. Since 204.9.88.0/21 is located at our transatlantic friends from US, there might be some problem with leaking privacy informations. I don’t feel happy, if I had a typo in my URL and getting listed for it on any terror list or providing the newest porno links to my american friends inside the organisations with the tree capitals. All that for getting some extra money, but racing pricedumping for connectivity, this sucks a lot.
If you are a customer and feel pissed, you can send a friendly note to them:

Kabel Deutschland Vertrieb und Service GmbH & Co. KG
Beschwerdestelle
99116 Erfurt
kundenservice@kabeldeutschland.de
Fax: 01805299925

A quick and dirty workaround for dnsmasq maybe to add “bogus-nxdomain=204.9.89.60″ to your config file. This doesn’t fix the DNSSEC problem.
The problem also pops up at dns-operations and there are traces at google too.

Conditional partitioning in debian installer I needed to create an automatic, unattended installer that would repartition the whole disk, but keep an existing home partition if it is already existing. The idea is to replace the operating system, but keep the user's home files. If the home partition does not exist, however, we need to create it. The starting point for this is in Holger's website, which does everything except create the partition if it's missing. The technique I used is to create a udeb that would scan the partitions using /usr/lib/partconf/find-partitions and then load the right preseeding for partman-auto, the automatic partitioner. Here you find the udeb source. I'll comment the most important bits: First, the two partman-auto recipes that we are going to preseed. The format is documented in the debian-installer documentation. This will create /home if missing: And this will keep /home if it exists: Then the postinst file of the package, where the logic is. Otavio and Daniel on #debian-boot have taught me that udebs are, simply put, just big postinsts (installer wise, apart from shipping binaries). Postinst is where the logic is done, or applications are started. Finally, debian/control. The basic bits about creating a d-i udeb are to put it in Section: debian-installer and to use XC-Package-Type: udeb. Then there is XB-Installer-Menu-Item, that defines the order of execution of postinsts. The d-i documentation lists the numbers that are currently assigned. I am using 38 rather than 3800 because I'm targeting etch d-i. After etch, "numbers have been multiplied by 100 from what they were before to give us more space". This is it. debian/rules is just boilerplate, except installing the preseed files in the right place. CDBS is useful to make this self-evident: To build the installer CD with this d-i, I'm using simple-cdd; here are the profile files I'm using at the moment, with the main preseeding for fully unattended install (it is designed to trash your hard disk if you boot it, so only test it in an emulated environment) and the inclusion of the custom udeb.

People don't seem to get that once you load a 1MB binary blob into your kernel you are no longer running a free operating system. There is no way to fix it. No way to see what is going wrong. Fedora 9 is shipping the latest xorg Release. It features major improvements for the Intel and Radeon drivers. The well known randr features got pushed even more. Plus gaining better 2D and 3D effects and important power saving improvements. Thanks to all the xorg hackers! Big blame on a unnamed company that can't keep up with latest Linux (Xen gained paravirt_ops support in 2.6.24 - oh yeah but we are still on 2.6.18 state). To truly support Linux you'd have to first release your specs and then help existing xorg hackers. Even Via seem to have got the message lately after years of no transparence.

I caught Swedish, so now I’m in 9^th position. Only 269 strings left for overtaking Spanish. Yes, I’m taking this as a competition :)

The first step is to copy /images/xen/vmlinuz and /images/xen/initrd.img from the Fedora (or RHEL or CentOS) DVD somewhere convenient, I use /boot/OS/ (where OS is the name of the image) but other locations will do. Now choose a suitable Ethernet MAC address for the interface (see my previous post on how I choose them [1]). Create a temporary block device for the install, I use /dev/VG0/OS-install (where OS is replaced by the name of the distribution, “f8” or “cent5“), it’s a logical volume in an LVM volume group named VG0. The device should be at least 2G in size for a basic Fedora install (512M for swap, 1G for files, and 512M free after the install). It is of course possible to use DOS partitions for the Xen block devices, but this would be unreasonably difficult to manage. An option for people who don’t like LVM would be to use files on an XFS filesystem (Ext3 performs poorly when creating and removing large files). When configuring Xen on Debian systems I generally use /dev/hda type device names. The device name seems quite arbitrary and /dev/hda is a familiar name for hard drives that many people have been used to for 15+ years. But the Fedora install process doesn’t like it and I’m forced to use /dev/xvda etc. I often install Fedora on a machine that only has 256M of RAM spare for the DomU. For recent versions of Fedora 256M of RAM is about the minimum for an install at the best of times, and a HTTP install takes even more because the root filesystem used for the install is copied via HTTP and stored in a RAM disk. It might be possible to use less RAM with a CD or DVD install or even a NFS install, but I couldn’t get CD/DVD installation working and I generally don’t give Xen DomU’s NFS access if I can avoid it. So I had to create a swap space (an attempt to do an install with 256M of RAM and no swap aborted when installing the kernel package). I expect that most serious use of Xen will have 256M of RAM or less for the DomU, part of the problem here is that Xen allocates RAM not virtual memory. VMWare allocates virtual memory so the total memory for virtual machines can be greater than physical RAM and thus this problem will be less common with VMWare. I believe that the best way of configuring virtual machine images is to have the virtual machine manager (Xen in this case) provide block devices to the virtual machine and have the virtual machine implement no partitioning (no LVM or anything equivalent). The main reason is that DOS partition tables and LVM configuration on a block device used by Xen can not be used easily in the host environment (the Dom0 for Xen). I am not aware of how to access DOS partition tables (although I’m sure it’s possible somehow) and while LVM can be used it’s a bad idea due to the fact that there is no way to deactivate a LVM volume group that is active, and the fact that there is no support for having multiple volume groups of the same name. The lack of support for multiple volume groups of the same name is a reasonable limitation, but an insurmountable problem when using a virtual machine environment. It’s quite reasonable to create several cloned instances of a virtual machine and renaming an LVM volume group would require more changes inside the virtual machine than you would want. Also using snap-shots of old versions of the virtual machine data is difficult if the same volume group name is used. So for ease of management I want to have filesystems on block devices (such as /dev/xvda) instead of partitions (such as /dev/xvda1). Unfortunately Anaconda (the Fedora installer) doesn’t support this. So I had to do the initial install with DOS partitions and then fix it afterwards. So use the manual option and create a primary partition for the root filesystem and then create a non-primary partition for swap (when using small amounts of RAM such as 256M) so that swap can be used during the install. The root filesystem needs to be at the start of the disk to make it easier to sort this out later. After installing Fedora and shutting the virtual machine down the next step is to copy the block device to the desired configuration (filesystem on an unpartitioned device). If the root filesystem is the first partition then the first 63 sectors will be the partition table and reserved space so dd can be used to copy the data with the following commands: dd if=/dev/VG0/OS-install of=/dev/VG0/OS bs=512 skip=63
e2fsck -f /dev/VG0/OS
resize2fs /dev/VG0/OS The next step is to mount the device /dev/VG0/OS in the Dom0 to change /etc/fstab, I use /dev/xvda for the root device and /dev/xvdb for swap. Now to remove the cruft:
Avahi is a network service discovery system, mainly used for laptops and isn’t needed on a server, it is installed by default on all recent Fedora, RHEL and CentOS releases but it is not useful in a DomU (any unused network service is a security risk if you don’t disable or remove it). Smartmontools is for detecting impending failure of a hard drive and does not do any good when using a virtual block device (you run it on the Dom0). It might be considered a bug that smartd doesn’t exit on startup when it sees a device such as /dev/xvda. The pcsc-lite package for managing smart cards is of no use to me and all the other people who don’t own readers for smart-cards, and it can therefore be removed. Bluetooth networking support (in the package bluez-utils) is also only usable in a Dom0 (AFAIK), and the only bluetooth device I own is my mobile phone so I can’t use it on my computer. The command “yum remove avahi smartmontools pcsc-lite bluez-utils” removes them. For almost all of my DomU’s I don’t use NFS or do any printing, so I remove the packages related to them. Also autofs is in most cases only useful for servers when mounting NFS filesystems. I remove them with the command “yum remove nfs-utils portmap cups autofs“. The GPM daemon (which supports cut/paste operations with a mouse on virtual consoles) is of no use on a Xen DomU, unfortunately the vim-enhanced package depends on it. I could just disable the daemon, but as I like to run small images I remove it with “yum remove gpm“. I may have to reinstall it on some images as some of my clients like the extra VIM functionality. It’s unfortunate that debootstrap doesn’t work on CentOS (and presumably Fedora) so installing a Debian DomU on a CentOS/Fedora Dom0 requires creating an image on a Debian machine or downloading an image from www.jailtime.org . Sample Xen Config for the install: kernel = “/boot/OS/vmlinuz”
ramdisk = “/boot/OS/initrd.img”
memory = 256
name = “OS”
vif = [ 'mac=00:16:3e:66:66:68, bridge=xenbr0' ]
disk = [ 'phy:/dev/VG0/OS-install,xvda,w' ]
extra=”askmethod text” Sample Xen Config for operation: kernel = “/boot/cent5/vmlinuz-2.6.18-53.el5xen”
ramdisk = “/boot/cent5/initrd-2.6.18-53.el5xen.img”
memory = 256
name = “cent5″
vif = [ 'mac=00:16:3e:66:66:68, bridge=xenbr0' ]
disk = [ 'phy:/dev/VG0/cent5,xvda,w', 'phy:/dev/VG0/cent5-swap,xvdb,w' ]
root = “/dev/xvda ro”

• [1] http://etbe.coker.com.au/2007/03/27/xen-and-eth-device-renaming/

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The CIO and the Office For Technology of New York State (USA) just released a new report on electronic records strategy, titled A Strategy for Openness: Enhancing E-Records Access in New York State. I submitted my own comments during the call for public comments earlier this year -- apparently there were only 114 comments submitted by the public (you can see the call for comments and an overview/analysis of the responses). I wish there'd been more, since it looks like the 59 individual commenters were overwhelmingly supportive of a requirement for the Gov't to use ODF. The rest of the comments were from governments, NGOs, and businesses, and they don't seem as unanimous as the individual commenters. Looking at the metadata for the executive summary shows just how far we have to go:

[0 dkg@squeak doc]$ pdfinfo PartIerecordsStudy.pdf    egrep '^Title Producer Creator'
Title:          Microsoft Word - PartIerecordsStudy.doc
Creator:        PScript5.dll Version 5.2.2
Producer:       Acrobat Distiller 8.1.0 (Windows)
[0 dkg@squeak doc]$ 

And in a message sent to commenters announcing the report, they seem to be aware that they're not quite doing their best at interoperability:

(Please note this is the first time any of NYS government's agencies has ever published a document in ODF format. We ran into problems this morning not caused by the format, but rather with some controls on our systems which were not prepared to encounter such documents. So the website links to ODF versions are not working at the moment, but will be repaired soon).

What web server are they running that is having trouble "encountering" ODF? No surprise:

[0 dkg@squeak doc]$ wget -S -O/dev/null 'http://www.oft.state.ny.us/policy/esra/erecords-study.htm' 2>&1   grep Server
  Server: Microsoft-IIS/6.0
[0 dkg@squeak doc]$ 

Sigh. My initial reaction to the report (i've only read the executive summary, not the supporting documentation) is disappointment. While they claim that "openness" is an important feature, they fall far short of taking a strong stand for free and open formats. The main thrust of the executive summary seems to be (paraphrasing here, i welcome corrections):

• it's a bad idea to mandate a single particular technology because technologies will change faster than law.
• we need an Electronic Records Committee (ERC) to provide regular, executive guidance on electronic record storage and maintenance
• "openness" is good, but needs to be weighed against (ill-specified, at least in the executive summary) "other features"
• we're not going to make any concrete recommendations about what to do next

While these are unsurprising conclusions, they don't take the strong stand i'd like them to take. They seem aware of the "chicken and egg" problem of wide adoption and vendor support, and aware of the anti-democratic effects of proprietary formats. But they don't seem to be willing to act as a catalyst to push free formats explicitly. If they did, they could break the chicken/egg vendor lock-in cycle and facilitate better open government practices while simultaneously encouraging a healthy information ecosystem. At this point, i suppose my biggest hope from the process is that the proposed ERC forms pilot groups with long-term goals modeled after Munich, but i'm not holding my breath. If there are any advocates or participants in the Munich process who want to share what's been working for you (and what hasn't), i'd be interested in hearing about it.Tags: government, odf, policy

The way Xen works is that the RAM used by a virtual machine is not swappable, so the only swapping that happens is to the swap device used by the virtual machine. I wondered whether I could improve swap performance by using a tmpfs for that swap space. The idea is that as only one out of several virtual machines might be using swap space, a tmpfs storage could cache the most recently used data and result in the virtual machine which is swapping heavily taking less time to complete the memory-hungry job. I decided to test this on Debian/Etch (both DomU and Dom0). Above is a graph of the time taken in seconds (on the Y axis) to complete the command “apt-get -y install psmisc openssh-client openssh-server linux-modules-2.6.18-5-xen-686 file less binutils strace ltrace bzip2 make m4 gcc g++“, while the X axis has the amount of RAM assigned to the DomU in megabytes. The four graphs are for using a real disk (in this case an LVM logical volume) and for using tmpfs with different amounts of RAM backing it. The numbers 128000, 196000, and 256000 and the numbers of kilobytes of RAM assigned to the Dom0 (which manages the tmpfs). As you can see it’s only below about 20M of RAM that tmpfs provides a benefit. I don’t know why it didn’t provide a benefit with larger amounts of RAM, below 48M the amount of time taken started increasing exponentially and I expected that there was the potential for a significant performance boost. After finding that the benefits for a single active DomU were not that great I did some tests with three DomU’s running the same APT command. With 16M of RAM and swap on the hard drive it took an average of 408 seconds, but with swap on the tmpfs it took an average of 373 seconds - an improvement of 8.5%. With 32M of RAM the times were 225 and 221 seconds - a 1.8% improvement. Incidentally to make the DomU boot successfully with less than 30M of RAM I had to use “MODULES=dep” in /etc/initramfs-tools/initramfs.conf. To get it to boot with less than 14M I had to manually hack the initramfs to remove LVM support (I create my initramfs in the Dom0 so it gets drivers that aren’t needed in the DomU). I was unable to get a DomU with 12M of RAM to boot with any reasonable amount of effort (I expect that compiling the kernel without an initramfs would have worked but couldn’t be bothered). Future tests will have to be on another machine as the machine used for these tests caught on fire - this is really annoying, if someone suggests an extra test I can’t run it. To plot the data I put the following in a file named “command” and then ran “gnuplot command“:
unset autoscale x
set autoscale xmax
unset autoscale y
set autoscale ymax
set xlabel “MB”
set ylabel “seconds”
plot “128000″
replot “196000″
replot “256000″
set terminal png
set output “xen-cache.png”
replot “disk” In future when doing such tests I will use “time -p ” (for POSIX format) which means that it displays a count of seconds rather than minutes and seconds (and saves me from running sed and bc to fix things up). I am idly considering writing a program to exercise virtual memory for the purpose of benchmarking swap on virtual machines. My raw data is below:

time apt-get -y install psmisc openssh-client openssh-server linux-modules-2.6.18-5-xen-686 file less binutils strace ltrace bzip2 make m4 gcc g++ 96M: 0m37.416s
64M: 0m47.607s
48M: 0m55.050s
32M: 1m8.200s
30M: 1m15.010s
28M: OOM process 2 with default initrd, needed MODULES=dep to make it boot
28M: 1m18.694s
24M: 1m25.517s
20M: 1m38.376s
16M: 2m15.594s
14M: 3m14.777s
13M: OOM when the initrd is not hacked to remove LVM stuff and drivers for Dom0 stuff
13M: 4m15.930s
12M: really won’t boot 128000K of RAM in Dom0 for caching (18M cache and 70M free), 256M swap per DomU on tmpfs. 96M: 0m40.121s
64M: 0m48.207s
32M: 1m12.394s
24M: 1m21.929s
16M: 1m59.042s
14M: 2m48.517s
13M: 3m29.391s 196000K of RAM in Dom0 for caching: 64M: 0m47.871s
32M: 1m12.078s
24M: 1m22.360s
16M: 2m0.336s
14M: 2m36.459s 256000K of RAM in Dom0 for caching: 64M: 0m47.949s
32M: 1m11.435s
24M: 1m21.402s
16M: 1m58.884s
14M: 2m39.081s 256000: of RAM in Dom0, three DomU’s: 32M: 3m41.583s 3m40.737s 3m41.071s
16M: 6m16.430s 6m14.832s 6m7.569s hard drive, three DomU’s: 32M: 3m42.100s 3m47.516s 3m46.333s
16M: 6m41.587s 6m50.837s 6m51.795s

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It’s not every day that your work is ignored by a founder of Mozilla Europe. From El Pa s:

En Espa a un 23,5% de visitas se dan en Firefox, un ndice que es superior al de EE UU, pero que no llega a los ndices de Polonia donde el 40% del tr fico se da en el navegador de Mozilla. A pesar de estos aceptables datos [Tristan] Nitot ha recordado y pr cticamente hecho un llamamiento para crear una versi n del navegador en gallego: “Hay una versi n en catal n de Firefox construidas por voluntarios que les importa su idioma, al igual que la hay de euskera. Pero a n no hay una versi n en Galicia, muchas veces me lo preguntan y mi respuesta es que si nadie de Galicia se presenta no habr una versi n en gallego, estamos dispuestos a que la gente trabaje con nosotros".

Loosely translated:

“There’s a Catalan version of Firefox built by volunteers who care about their language, and there’s another one in Basque. But there’s no Galician version yet, I get asked this very often, and my answer is that if nobody from Galicia steps up there will be no Galician version. We would like people to work with us".

So, apparently, there’s no Galician translation of Mozilla. I guess that my more than three years’ worth of work were wasted (Dec 2001 - Jul 2004 and Jan 2006 - Aug 2006), that Xis and Galego21 did nothing back in the nineties and noughties, and that what mancomun.org is hosting is an empty XPI file. To not speak of the paralysed/paralysing bureaucracy of the Mozilla Foundation when several groups of volunteers, one after the other, tried to reinstate the official Galician l10n team. I would be pissed off if I cared about Galician. Because, you know, from reading my blog it’s obvious I don’t.