It s generally accepted that certain things need redundancy. RAID is generally regarded as essential for every server except for the corner case of compute clusters where a few nodes can go offline without affecting the results (EG the Google servers). Having redundant network cables with some sort of failover system between big switches is regarded as a good idea, and multiple links to the Internet is regarded as essential for every serious data-center and is gaining increasing acceptance in major corporate offices. Determining whether you need redundancy for a particular part of the infrastructure is done on the basis of the cost of the redundant device (in terms of hardware and staff costs related to installing it), the cost of not having it available, and the extent to which the expected down-time will be reduced by having some redundancy. It s also regarded as a good idea to have more than one person with the knowledge of how to run the servers, jokes are often made about what might happen if a critical person fell under a bus , but more mundane things such as the desire to take an occasional holiday or a broken mobile phone can require a backup person. One thing that doesn t seem to get any attention is redundancy in the machine used for system administration. I ve been using an EeePC [1] for supporting my clients, and it s been working really well for me. Unfortunately I have misplaced the power supply. So I need to replace the machine (if only for the time taken to find the PSU). I have some old Toshiba Satellite laptops, they are quite light by laptop standards (but still heavier than the EeePC) and they only have 64M of RAM. But as a mobile SSH client they will do well. So my next task is to set up a Satellite as a backup machine for my network support work. It seems that this problem is fairly widespread. I ve worked in a few companies with reasonably large sysadmin teams. The best managed one had a support laptop that was assigned to the person who was on-call outside business hours. That laptop was not backed up (to the best of my knowledge, it was never connected to the corporate LAN so it seems that no-one had an opportunity to do so) and there was no second machine. One thing I have been wondering is what happens to laptops with broken screens when the repair price exceeds the replacement cost. I wouldn t mind buying an EeePC with a broken screen if it comes with a functional PSU, I could use it as a portable server.

• [1] http://etbe.coker.com.au/2008/07/21/review-of-the-eeepc-701/

Our inaugural R / Finance conference, mentioned here twice is now over. We were fortunate to get seven outstanding invited keynote speakers, as well as eleven excellent presentations. This was preceded by four short tutorials (and I'll post slides from my Introduction to High-Performance Computing with R soon). With about 150 registered participants, plus keynoters, presenters, committee members, representatives from the sponsors (a quick shout of Thanks! to them), some folks from UIC (especially Holly without whom few things would have happened), we were probably around 200 people gathered at UIC. And then there was an extended social program at Jaks which is rather appropriate as we had numerous important committee meetings there over the preceding months. All in all it seems like a successful event. We may even do it again.

previously i threw together a small hook to make it a bit easier to avoid duplicate work while maintaining packages, as well as easily keep the BTS up to date with relevant information. now i've commonized the code just a bit and have a second hook which can be used to maintain certian (what i believe to be) good practices for keeping packages in git. admittedly, it's a bit more "stick" than "carrot" with respect to streamlining workflows, but i feel the justifications and the resulting benefits are worth it. so the hook does basically two things, either of which can be customized and/or disabled. prevent "non-debian" changes on a "debian" branch assuming that there are seperate branches for "debian" packaging and for "upstream" development, this hook prevents upstream-style changes on the debian branches. that is to say changes to files outside ./debian are not permitted on a "debian" branch, unless of course you're merging from an upstream branch. instead, changes to the source in a debian branch should be managed by quilt-style "feature patches", or a more advanced branch topology using some kind of feature branches (topgit or similar). prevent changelog modifications from being mixed in with other commits this one might be a bit more controversial for some. basically, the idea is that:

• stuff is fixed in a commit
• there is a log message for this commit, which contains a description of the fix
• the changelog update is redundant information to this log
• it's impossible to merge/cherry-pick/revert the fix later if the changelog gets tangled into the commit.
• there are nice tools (git dch) for managing debian/changelog updates anyway.

therefore, this hook "declines" commits which modify debian/changelog, unless it is the only file being changed. using this new hook note this is the same repo as the other hook, so if you already have that set up you can skip the clone and instead just pull in the changes. to set it up:

REPO_PATH=/path/to/your/repo.git
HOOK_REPO_PATH=/somewhere/you/want/to/put/it
git clone git://git.debian.org/users/seanius/vcs-hooks/git-hooks.git $HOOK_REPO_PATH
ln -sf $HOOK_REPO_PATH/debian/git-hooks/pre-receive-fileset-fascism.py $REPO_PATH/hooks/pre-receive

the config options for controlling this hook (these are git config options just like the other hook):

# hooks.debianbranches (default: 'debian-.*')
#    a regular expression which indicates which branches are "debian" branches.
#    in the context of this hook such branches are not allowed to have changes
#    in files outside of the ./debian directory.
# hooks.sacredchangelog (default: True)
#    if set to True, debian/changelog can not be changed in a commit that
#    also modifies other files.  this helps ensure changes that are easily
#    merged/cherry-picked/reverted.

examples of the hook in action rejecting a commit that has an entangled changelog:

rangda[~/debian/php] git push                                  :)
Counting objects: 9, done.
Delta compression using 2 threads.
Compressing objects: 100% (5/5), done.
Writing objects: 100% (5/5), 442 bytes, done.
Total 5 (delta 4), reused 0 (delta 0)
fileset-fascism rejecting commit 2fab3269b3d9daedd7013a576483a11ccb4cb86a
    debian/changelog must be changed seperately from other files.
    changed files in this commit:
        debian/changelog
        debian/control
error: hooks/pre-receive exited with error code 1
To ssh://git.debian.org/git/pkg-php/php.git
 ! [remote rejected] debian-sid -> debian-sid (pre-receive hook declined)
error: failed to push some refs to 'ssh://git.debian.org/git/pkg-php/php.git'

rejecting a commit that has non ./debian changes:

rangda[~/debian/php] git push                                  :)
Counting objects: 5, done.
Delta compression using 2 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (3/3), 309 bytes, done.
Total 3 (delta 2), reused 0 (delta 0)
fileset-fascism rejecting commit d96669c0780e33b250af81404e263fc181fe0547
    non ./debian changes on a debian branch in this commit.
error: hooks/pre-receive exited with error code 1
To ssh://git.debian.org/git/pkg-php/php.git
 ! [remote rejected] debian-sid -> debian-sid (pre-receive hook declined)
error: failed to push some refs to 'ssh://git.debian.org/git/pkg-php/php.git'

as always, comments/feedback/suggestions/etc welcome

Finally I was able to clean up one of my m68k buildds: Spice. Actually I regularly clean up all of my machines so they continue to work properly. Usually I do this maintenance work every year around christmas, but this time was different. Anyway. I took some pictures:



In fact I assumed more dust inside after 512 days of uptime, but I was suprised that the dust was moderate. So the cleaning was easy and fast. This is the result:



Next and final step was to enable the Laptop mode. Sadly there was no /proc/sys/vm/laptop_mode, but the final solution wasn't that difficult either to have a portable Amiga 3000:



Well, the reason for that Laptop mode is quite simply: although the A3000 is quite silent with its Papst fan, its SCSI/SCA disks aren't. To safe some noise I plan to move the A3000/autobuilder to the guestroom, but when there's some visitors, I want to be able to relocate the machine without interrupting the build. So attaching a UPS and a wireless bridge is the way to go for this purpose.

So, when I like something, I tend to yap about it for weeks and weeks. Take Icelandic Yogurt, for example. After re-discovering it a month ago, I went on a mini-binge (not a mega as it is too expensive) and spread the word to anyone who would listen. The stuff, especially with fun flavors like ginger and orange, just made my morning. Another fine fine thing out there is the performance group What We Know So Far who give performance-based lectures that mix intellectual insight with artistic flair. They put us regular academics to shame who are a bit more staid, to put it mildly. After seeing them a few weeks ago at the 3rd Ward, I snagged them to give a version of their A-mazing talk on Memes in my class and am organizing a much larger event at NYU for the fall of 2009. This is a sort of long winded way of announcing their up and coming show on April 27th the Hannah Complex, which entertains, among other topics, the nature of common sense: Can there be more than one common sense? they ask on their site. And I can t wait to hear the answer as this is a recurrent topic that anthropologists like to entertain. And in fact one of my favorite essays to teach is on this topic, Clifford Geertz Common Sense as Cultural System, a short excerpt which I found here and below is his thesis in a nutshell:

There are a number of reasons why treating common sense as a relatively organized body of considered thought, rather than just what anyone clothed and in his right mind knows, should lead on to some useful conclusions; but perhaps the most important is that it is an inherent characteristic of common-sense thought precisely to deny this and to affirm that its tenets are immediate deliverances of experience, not deliberated reflections upon it. Knowing that rain wets and that one ought to come in out of it, or that fire burns and one ought not to play with it (to stick to our own culture for the moment) are conflated into comprising one large realm of the given and undeniable, a catalog of in-the-grain-of-nature realities so peremptory as to force themselves upon any mind sufficiently unclouded to receive them. Yet this is clearly not so. No one, or no one functioning very well, doubts that rain wets; but there may be some people around who question the proposition that one ought to come in out of it, holding that it is good for one s character to brave the elements hatlessness is next to godliness. And the attractions of playing with fire often, with some people usually, override the full recognition of the pain that will result. Religion rests its case on revelation, science on method, ideology on moral passion; but common sense rests its on the assertion that it is not a case at all, just life in a nutshell. The world is its authority.

So, when I like something, I tend to yap about it for weeks and weeks. Take Icelandic Yogurt, for example. After re-discovering it a month ago, I went on a mini-binge (not a mega as it is too expensive) and spread the word to anyone who would listen. The stuff, especially with fun flavors like ginger and orange, just made my morning. Another fine fine thing out there is the performance group What We Know So Far who give performance-based lectures that mix intellectual insight with artistic flair. They put us regular academics to shame who are a bit more staid, to put it mildly. After seeing them a few weeks ago at the 3rd Ward, I snagged them to give a version of their A-mazing talk on Memes in my class and am organizing a much larger event at NYU for the fall of 2009. This is a sort of long winded way of announcing their up and coming show on April 27th the Hannah Complex, which entertains, among other topics, the nature of common sense: Can there be more than one common sense? they ask on their site. And I can t wait to hear the answer as this is a recurrent topic that anthropologists like to entertain. And in fact one of my favorite essays to teach is on this topic, Clifford Geertz Common Sense as Cultural System, a short excerpt which I found here and below is his thesis in a nutshell:

There are a number of reasons why treating common sense as a relatively organized body of considered thought, rather than just what anyone clothed and in his right mind knows, should lead on to some useful conclusions; but perhaps the most important is that it is an inherent characteristic of common-sense thought precisely to deny this and to affirm that its tenets are immediate deliverances of experience, not deliberated reflections upon it. Knowing that rain wets and that one ought to come in out of it, or that fire burns and one ought not to play with it (to stick to our own culture for the moment) are conflated into comprising one large realm of the given and undeniable, a catalog of in-the-grain-of-nature realities so peremptory as to force themselves upon any mind sufficiently unclouded to receive them. Yet this is clearly not so. No one, or no one functioning very well, doubts that rain wets; but there may be some people around who question the proposition that one ought to come in out of it, holding that it is good for one s character to brave the elements hatlessness is next to godliness. And the attractions of playing with fire often, with some people usually, override the full recognition of the pain that will result. Religion rests its case on revelation, science on method, ideology on moral passion; but common sense rests its on the assertion that it is not a case at all, just life in a nutshell. The world is its authority.

I was invited to talk about Free Software at yesterday's FLISOL. Yesterday? Aren't FLISOLs organized on Saturday? Well, not this one, for various reasons which I won't quote here. And no, I am not a supporter of the installfests idea, but I went gladly to talk about what is Free Software all about - The philosophy behind Free Software. Besides, the talk was at FES Iztacala, where I worked for four happy years, 1999-2003. I have not been often to Iztacala since 2003 (probably I have visited only three or four times), partly because of the distance (~25Km from home in a straight line, but the city's Northern part is quite poorly communicated). The last time I was there, last October, I went by bike, just to test my endurance and... because I could. Yesterday, I also did, not to be outdone by my fellow Debianers Christian and Dirk. Think they are so cool because they can run for 43Km? Well, I had my 55Km yesterday, and I was not even in a competition! (yes, yes, running and biking is not the same. So sue me. I just didn't want to stand still and let them walk away with all of the fun!) I took slightly different routes (my route to get there on Nokia Sportstracker and OpenStreetMap trace, my route back on Nokia Sportstracker and OpenStreetMap trace), crossing diagonally Azcapotzalco, a region of the city (delegaci n) I hardly know... The Sourthern of it seems like a continuation of Tacuba to the North, small and not-very-well-communicated prior villages engulfed by our hungry, huge city. The Northern half is a mostly industrial area, with very sparse population, lots of trucks, and streets that are not in the best shape. You can end up feeling lonely in those regions, and I am glad not to have crossed back by night. And the trip back was interesting as well... Mexico City is home to many more bikers you would expect given its size, and it is very common to find other people doing nice long stretches. In this case, I started cycling quite close to another guy in a white bike more or less when I got to Calzada Camarones. Possibly we had passed each other over and over until after Tlatelolco, arriving to Guerrero, where I approached him at a stoplight:
Hi! Where to?
Near Vocacional 7, Iztapalapa!
Nice! I'm just going to Copilco Every now and then we crossed each other... Turns out he does this ~30Km commute daily between Iztapalapa and Azcapotzalco. Quite admirable, to be honest. I also crossed my road with Sergio Mendoza, fellow Debianer (and co-administrator of our Mexican mirror) around Centro M dico (about 7Km north from my destination), whom I had only seen before around the University. Nice surprise. And yes, getting to know the city by bike is the best way to go! Back to the conference... my first thought when I was invited was to present Qu es el Software Libre?, a talk I have given over and over since... 2002 (although, yes, with updates). I must say it's one of the best structured talks I have prepared and has almost always been very successful - But give the same talk based on the same script over and over (AFAICT, around 20 times), and you will be fed up with it. And yes, yesterday I didn't take my laptop along, and didn't put my presentation on a USB stick - I took a pen and some paper, and during the presentation prior to mine, wrote some points to go over. And yes, it was a refreshing change. The talk was as successful as expected, and it's much more refreshing to talk about the same topics bot on a different way, and without being constrained to a predefined script. I know that organizing formally your ideas makes sure you don't miss out important points and that the audience is sometimes encouraged to pay attention by having some bullet points to look at - But on the other hand, it is much easier to follow your audience's interest if you are not bound by the script. And the few times I've spoken that way, it has felt refreshing and nice.

dput + mini-dinstall to ease people.d.o uploads As DDs we often want to offer unofficial packages, but still preserving a bit of "authoritativeness". A widespread solution is to upload somewhere under http://people.debian.org/~LOGIN as an APT repository. I've been using that solution too since ... ever, but I've never been happy about how to advertise the packages, probably just because I've never liked dpkg-scan packages,sources and hackish scripts built on top of them. My goal, as simple as it can be, is to work as I do to prepare "real" packages to be uploaded to the Debian archive, and just upload to people.d.o as the final step. Thanks to DSA which satisfied a request of mine by installing a while ago mini-dinstall on ravel, today I've finally set up a work-flow that enabled me to reach my goal. This post is a quick howto to implement that setup. If you have suggestions about where (wiki.d.o? devref?) to paste these info so that other DDs can more easily find them in the future, please let me know, via comments or mailing me. Step 1: configure mini-dinstall on people.debian.org On people.debian.org, create a ~/.mini-dinstall.conf file containing something like the following:

    [DEFAULT]
    mail_to = zack
    incoming_permissions = 0750
    architectures = all, i386, amd64
    archive_style = flat
    dynamic_reindex = 1
    archivedir = /home/zack/public_html/debian/
    generate_release = 1
    release_origin = Zack
    release_label = Zack
    release_description = Unofficial Debian packages maintained by Stefano Zacchiroli
    [zack-unstable]
    release_suite = zack-unstable

Highlights of that conf:

• "flat" archive style means "all in one dir", a more structured alternative is "simple-subdir"
• you request to generate a Release file, which is needed for the secure APT machinery; various fields of that file are specified by the release_* options
• you call your suite "zack-unstable" (well, I do ). That suite must match the distribution in your debian/changelog entries. In theory you can use legacy names such as "unstable", but as we are humans and we make mistakes, better to use invalid suite names that will be refused by dak if you upload to the wrong queue

The resulting repository will be accessible using the following /etc/apt/sources.list lines:

    deb http://people.debian.org/~zack/debian zack-unstable/
    deb-src http://people.debian.org/~zack/debian zack-unstable/

Step 2: configure dput The default incoming dir of mini-dinstall, relative to the configured archivedir, is mini-dinstall/incoming. The following entry for your ~/.dput.cf (on the machine you upload from) will therefore setup your dput for uploads:

    [people.debian.org]
    fqdn = people.debian.org
    method = scp
    login = *
    incoming = /home/zack/public_html/debian/mini-dinstall/incoming
    post_upload_command = ssh people.debian.org mini-dinstall -b

The only interesting detail here is the post upload command, which will run a "pulse" of mini-dinstall on people.d.o just after the upload, to process the uploaded file. Alternatively, you can leave mini-dinstall running on people.d.o, but I consider it unnecessary (because usually you are the only one able to upload to your home dir), unelegant, and complicated (because you then need to verify mini-dinstall is running). Step 3: enjoy (i.e., upload) Now you can prepare your packages as you always do (which means using cowbuilder!) and, when you are done with your foo_1.0-1_amd64.changes, upload it doing:

    $ dput people.debian.org foo_1.0-1_amd64.changes

Signing the Release file The above setup does not sign Release files, which means your APT users will receive complaints from the secure APT machinery. To fix that you must sign the Release file with some key and distribute the key to your users to be processed by apt-key add. You have a couple of ways to sign the release file automatically:

1. (/me doesn't like this) use a GPG key created for the occasion, store that key (including the private part) on people.d.o, and use the mini-dinstall contrib script sign-release.sh by adding something like the following to your mini-dinstall.conf:

     release_signscript = ~/bin/sign-release.sh
   
   

2. (/me likes this) use some script to sign the Release file remotely and send the resulting deatched signature back to people.d.o just after the mini-dinstall pulse; that way you can sign with your own private key, which will be reasonably felt as more trustworthy, being part of the Debian keyring. To achieve that, the most elegant way would be to fix debsign wishlist #465240 (volunteers? ). As I'm lazy, I'm using my own sign-remote script, which is a bit more generic. Remote signing should be attached to dput upload hook as well. All in all, here is my actual ~/.dput.cf stanza:

     [people.debian.org]
     fqdn = people.debian.org
     method = scp
     login = *
     incoming = /home/zack/public_html/debian/mini-dinstall/incoming
     post_upload_command = ssh people.debian.org "mini-dinstall --batch" && sign-remote people.debian.org:~/public_html/debian/zack-unstable/Release
   
   

Enjoy! Update: do both mini-dinstall run and signing in post_upload_command, following gregoa's suggestion via comment

This article from the Boston Globe gives an excellent description of what running Boston last Monday was like, and why we keep coming back, almost regardless. The writer, for whom it was the fifth Boston and ninth total, expresses the range of emotions, expectations, frustrations, excitements, ups, downs, ... all of which form the challenge of racing a marathon in general, and on this course on a windy day in particular. And just like she concludes that the finish of one marathon leads to planning the next, I registered last night for the Chicago Marathon on October 11, apparently around twelve hours before it sold out. And so it is with regrets that I have to decline Christian's invitation to run Cologne with him on October 4. Another time, hopefully.

Finding power and internet to post to a blog while hiking for half a year up the Appalachian Trail doesn't seem like a very likely combination, but nowadays some people manage it in various ways. I've read and enjoyed three or four books about AT thru-hikes, but blogs are a more immediate, interactive medium. I've been following with interest a group who came down with food poisoning as they hiked along the Holston Mtn. ridge in my "backyard" and look forward to reading about others as they pass by. So, I'm aggregating all such blogs I can find for the 2009 season on a page I call Planet A.T.. It's a nice way to read these contrasting accounts juxtaposed together in real time. One includes cell phone photos and fairly frequent updates of a hiker who's already reached Damascus; another is frequently updated by Blackberry by a guy I could well have crossed paths with on Roan this week; another has more infrequent, interesting long essays by a hiker who has just reached Tennesee; another is a teacher sending educational videos home to his school. There's even an 86 year old who I understand is the oldest person to hike the whole trail -- and is doing it again. I thought I'd only find a few blogs, but I've now added over a hundred! So maybe one in ten of all thru-hikers this year have a blog. And the number of bloggers will presumably dwindle toward twenty-five before they reach the end in Maine.

Now, I'm registered for Cologne Marathon. So is No l and probably Ralf Treinen. Any other DD or Debian contributors wanting to join in? I know that Dirk Eddelbuettel will probably not (btw, nice run at Boston, Dirk)....but others certainly can...and should ! October 4th, 2009 is still far enough for you guys to plan this..:-)

---

There is a Social Enterprise summit in London in May with cabinetoffice.gov.uk/thirdsector. As part of representing TTLLP to Cooperatives-SW, I will be at a regional workshop this afternoon to enable the sector to input the summit (?). More detail is available at tinyurl.com/cnm5c3 The workshop topics are

• fighting the recession ;
• social enterprise informing a rebalanced economy ;
• supporting new blood in social enterprise and
• scaling up the sector .

If you have any thoughts on those themes, please send them to me by IM, microblog or as a comment on this article. I may be commenting on identi.ca if I get internet at the event.

P. W. Singer gave an interesting TED talk about the use of robots in war [1]. He briefly covered some of the ethical and social issues related to robot soldiers as well as showing many pictures of existing robots. Since November 2007 there has been a request for Google Gears to support Iceweasel (the Debian name for Firefox due to trademark issues)[2]. Apparently supporting this different name is not easy for the Google people. If you visit the Google Gears Terms and Conditions page [3] then it will work with Iceweasel on the i386 platform - but not for AMD64 (or at least not my Debian/Lenny AMD64 system). Charles Moore gave a disturbing TED talk about the Great Pacific Garbage Patch [4]. Pollution in the oceans from waste plastic is worse than I realised. Ressuka documented how to solve the Time went backwards problem on Xen DomUs [5]. Run echo jiffies > /sys/devices/system/clocksource/clocksource0/current_clocksource or use clocksource=jiffies in your DomU kernel boot parameter list. Nassim Taleb [6] has written Ten principles for a Black Swan-proof world [7], this is in regard to the current US financial crisis. It s worth noting that he made a significant amount of money due to successfully predicting some aspects of the crisis. James Duncan Davidson has some good advice for speakers based on his experience in filming presentations [8]. Some of the ones that were not obvious to me were:
Take off your name-tag - it doesn t look good
Stay in the part of the stage with the best light

• [1] http://www.ted.com/index.php/talks/pw_singer_on_robots_of_war.html


• [2] http://code.google.com/p/gears/issues/detail?id=313


• [3] http://gears.google.com/terms.html?platform=linux


• [4] http://www.ted.com/index.php/talks/capt_charles_moore_on_the_seas_of_plastic.html


• [5] http://ressukka.net/blog/posts/20090305_XenServer_and_non_citrix_kernels/


• [6] http://en.wikipedia.org/wiki/Nassim_Taleb


• [7] http://www.fooledbyrandomness.com/tenprinciples.pdf


• [8] http://duncandavidson.com/2009/03/dear-speakers.html

Almost two years ago I blogged about a strange performance problem with SATA disks [1]. The problem was that certain regions of a disk gave poor linear read performance on some machines, but performed well on machines which appeared to be identical. I discovered what the problem was shortly after that but was prevented from disclosing the solution due to an SGI NDA. The fact that SGI now no longer exists as a separate company decreases my obligations under the NDA. The fact that the sysadmins of the University of Toronto published all the most important data entirely removes my obligations in this regard [2]. In their Wiki they write after SGI installed rubber grommits around the 5 or 6 tiny fans in the xe210 nodes, the read and write plots now look like and then some graphs showing good disk performance appear. The problem was that a certain brand and model of disk was particularly sensitive to vibrations. When that model of disk was installed in some machines then the vibrations would interfere with disk reads. It seems that there was some sort of harmonic frequency between the vibration of the disk and that of the cooling fans which explains why some sections of the disk were read slowly and some gave normal performance (my previous post has the graphs which show a pattern). Some other servers of the same make and model didn t have that problem, so it seemed that some slight manufacturing differences in the machines determined whether the vibration would affect the disk performance. One thing that I ve been meaning to do is to test the performance of disks while being vibrated. I was thinking of getting a large bass speaker, a powerful amplifier, and using the sound hardware in a PC to produce a range of frequencies. Then having the hard disk securely attached to a piece of plywood which would be in front of the speaker. But as I haven t had time to do this over the last couple of years it seems unlikely that I will do it any time soon. Hopefully this blog post will inspire someone to do such tests. One thing to note if you want to do this is that it s quite likely to damage the speaker, powerful bass sounds that are sustained can melt parts of the coil in a speaker. So buy a speaker second-hand. If someone in my region (Melbourne) wants to try this then I can donate some old IDE disks. I can offer advice on how to run the tests for anyone who is interested. Also it s worth considering that systems which make less noise might deliver better performance.

• [1] http://etbe.coker.com.au/2007/06/27/strange-sata-disk-performance/


• [2] http://wiki.cita.utoronto.ca/mediawiki/index.php/Xe

While shopping at Highpoint [1] today I noticed that they had a new loyalty system. It s called Mo Rewards [2] (for which the real web site is at MoCoMedia.net [3] which has no link from the main site because they didn t care enough about their web presence). The way that Mo works is that everyone gets a free RFID token similar to the two in the above photograph. The token comes with a pseudo-random seven letter code that you have to SMS to register it to your phone. You SMS the code and then receive a confirmation SMS. After that you can wave your token near a detector any time you visit the shopping center and you will receive three SMS messages with discount offers. You can send an SMS with your gender and birth-year to receive more targeted offers. To redeem offers you have to wave your token near a detector at the store so they know who is using the offers. Then of course once the database knows that you are a regular customer at a certain shop they can send you targeted advertising to entice you to buy from that shop on every visit. I presume that they have some sort of bidding system for adverts from the shops of a similar nature to the Google advertising. It s an interesting system and a lot better than most loyalty programs. One interesting thing about this is that high quality RFID devices are being given out for free. The tokens are quite solidly constructed and could be used for a variety of other purposes. I couldn t find anyone offering RFID tags at a reasonable price with a quick Google search (the cheapest was $75 for 100 tags - and they were the fragile ones used for marking stock in shops). So a hobbyist who wanted to do some RFID stuff could buy a cheap reader under one of the demo offers (where you get a reader and a small quantity of keys for a reasonable price) and then collect free RFID tokens from shopping centers. I expect that the number of people who would do such things is small enough to not be statistically significant and therefore not affect the business model. The tags are given out freely with no requirement that you must use them for the expected purpose (Mo Rewards) instead of using them for your own RFID work.

• [1] http://www.highpoint.com.au/


• [2] http://www.morewards.com.au/


• [3] http://www.mocomedia.net/

So. On Sunday, we worked through some of the bugs filed against KDE in Debian. Mostly, we cleaned up in old cruft, and a few bugs got forwarded. A bunch of the Debian KDE people participated, and some KDE Bugsquad people also dropped by. And a special thanks goes to the apparant newcomer, Karl Ferdinand Ebert, for doing a fantastic work, and I also succeeded in getting Anne-Marie Mahfouf to take a look at the kdeedu reports. We cleaned up in kdegraphics, kdeedu, kdeadmin and akregator reports, and did quite some work on the bug magnets of konqueror, kmail and kopete. Total result was around 100 bugs down, and we discovered a few bugs that had hidden in between the others, that is actually packaging issues.
All in all a success, that definately should be repeated in a month or two.

Doesn t this class look great??

Department of History Workshop MEDIA AND COMMUNICATION IN THE MIDDLE AGES Professor Brigitte M. Bedos-Rezak Medieval circumstances presented multiple challenges to media, mobility, and communication. Cultivators were bound to the land and monks to their monasteries; pilgrims traveled to holy places, crusaders and warriors invaded and then settled foreign lands, rulers and nobles were frequently itinerant. Literacy was largely limited to Latin, and possessed principally by churchmen and nuns so the transmission of ideas occurred mainly through the spoken vernacular word, and by means of gestures, images, and the manipulation of symbolic objects (thus, for instance, the relics of saints were carried to distant lands to collect alms, to recover possessions appropriated by nobles, or to aid in battle). While seas, rivers, ports, networks of roads provided with rest houses, ferries and bridges, were generally available, routes and means of transportation selected differed markedly according to the traveler s status and the journey s purpose. Christianity stimulated pilgrimages, missions to convert the heathen, and crusades. Marriage took brides to foreign courts where they served as cultural ambassadors. Medieval kings and great nobles were continually on the road, changing their abode every two or three days. Lesser officials and messengers traveled on government business. Knights sought out tourneys and distant wars to advance their fortunes and reputations. Merchants and carriers transported goods to regional fairs, and engaged in international trade. Minstrels, jongleurs, and troubadours traveled to gain patronage and to extend their repertoire, spreading news and influencing the reputations of warriors, heroes, and kings. Students too journeyed extensively from place to place in order to sit at the feet of famous masters; some wandering scholars came to be known as Goliards. Artists were invited to decorate manuscripts and architects to erect buildings.
The pursuit of favorable opinion became an essential feature in the process of state-building during the Middle Ages. Those who challenged traditional norms also came to rely on the efficiency of communicative systems to expand their ranks with adherents. Through the use of propaganda, medieval society experimented with such forms and methods of communication as symbols, stereotypes, and slogans, thus elaborating features of communication which, however modified, are still in use today.

Following to the email sent regarding the French law known as HADOPI (I blogged about it a few weeks ago), I had a meeting this afternoon with my local representative. This half an hour meeting allowed me to explain my fears regarding this firewall which could be set up on French citizens computers to enable them to prove their non-culpability (provided their computer runs a popular proprietary OS). My representative kindly listened to me and his assistant understood the situation very well. I was even impressed that they have worked a lot on this law before the meeting. They both proposed to raise this issue to Christine Albanel, the current French Minister for Culture and Communication, who is at the origin of this law. They agreed to say that this wouldn t be changed for the next lecture (planned for the end of the month), as this particular chapter was meant to be detailed in further texts. They also admitted that this law had little chance to be really applied as is, as they consider some aspects to be anti-constitutional - they hence think that the French Constitutional Council will prevent this law to be applied, at least as it is when writing this post.
My representative also admitted that this law was somewhat outdated (even if not yet voted!). Actually, this kind of law will ever be outdated I kindly thank my representative for his time and his frankness (even if on the bad side for this law, he was very open to my thoughts). Good to know France is still a real Democracy!