Search Results: "tar"

13 August 2008

Eddy Petrișor: migrating from svn to git for wormux's maintainance

I have been thinking for quite some time about migrating the maintenance of the wormux package to git, but in a really smart way so that:
Since both the package repo and the upstream repo are in SVN, you can't simply use git-svn for both in a single repo, so I started thinking of some scheme to be able to join both repos and the (uncommitted) orig tarballs (which are backed up on DGT's webspace).


Tonight I have experimented a little with my git-svn clones which I made previously and eventually thought that:

It seems the last point could be obtained in some way via this small set of commands (I am sure it needs some modification to make the integration work in another branch C):

git merge --no-commit -s ours B
git checkout B -- .
git checkout A -- .
git commit


Note: Looking back, I think I can do a better job next time and I will se if I can use the resulting repo to create a new repo and drop the svn package maintainance for wormux. If this works, I might be able to create a script to allow migration of svn-bp maintained packages to git, at least for the Debian Games Team.


Since you can't fix a problem if you don't take things one at a time, I started by cloning the initial git-svn generated repos.

So after waiting some time (both git-svn fetch commands took long enough), I had to git-svn repos:
I tried to clone both A and B, to avoid distroying the original A and B clones and noticed that the svn branches were not visible from the cloned repo since the origins didn't had any other local branches than master - the svn trunk for each of them. So I added tracking branches in A for the experimental and sarge versions of the package. I also added some tags in A so that the svn tags don't get lost in between.

In the end I got my A' repo that had:

0 eddy@heidi ~/usr/src/wormux/tt/debian-bare $ git br -a
debian-experimental
debian-sarge
debian-sid
* master
origin/debian-experimental
origin/debian-sarge
origin/master

Yes, and having master in A' is not a good idea, but since I made A' a bare repo I had to suffer. Well, one more thing to better in iteration 2.


Excellent, now I can go in B and add the new remote repo which is A' which I should have called pkgsvn, but I ended up call it 'origin'. Since git-svn doesn't treat the svn repo as a true remote, this was possible.



Due to some confusion I also added 'ups-' as a prefix to the svn remote trunk and tags, but I am still unsure if this was necessary - I'll have to see more clearly into the pristine-tar restrictions area.

After all of this I got this branch configuration:
0 eddy@heidi ~/usr/src/wormux/tt/git-full $ git branch
* master
0 eddy@heidi ~/usr/src/wormux/tt/git-full $ git branch -r
0.8-final
0.8beta4
origin/debian-experimental
origin/debian-sarge
origin/debian-sid
origin/master
ups-tags/wormux-0.7
ups-tags/wormux-0.7.2
ups-tags/wormux-0.7.3
ups-tags/wormux-0.7.4
ups-tags/wormux-0.7.9
ups-tags/wormux-0.7.9rc1
ups-tags/wormux-0.7beta3
ups-tags/wormux-0.8
ups-tags/wormux-0.8alpha1
ups-tags/wormux-0.8beta1
ups-tags/wormux-0.8beta2
ups-tags/wormux-0.8beta3
ups-tags/wormux-0.8beta4
ups-trunk
wormux-0.7
wormux-0.7.9
wormux-0.8beta1
wormux-0.8beta2

So more tracking branches were necessary; I fired 'gitk --all' and got a nice picture, after adding tracking branches for branches originating from A':


This is not yet complete and now I am feeling sleepy, so I'll continue once I experiment more.

Michael Schultheiss: schultmc = old

Tonight was the Debian 15th Anniversary Party and formal dinner over at the alternate hotel. During dinner, Bdale asked helix which Wilson Sister she thought she was most like. read more

Russell Coker: Starting to Blog

The best way to run a blog is to run your own blog server. This can mean running an instance on someone else’s web server (some ISPs have special hosting deals for bloggers on popular platforms such as Wordpress), but usually means having shell access to your own server (I’ve previously written about my search for good cheap Xen hosting [1]). There are platforms that allow you to host your own blog without any technical effort. Three popular ones are Wordpress.com, LiveJournal.com, and Blogger.com. But they give you less control over your own data, particularly if you don’t use your own DNS name (blogger allows you to use their service with your own DNS name). Currently it seems to me that Wordpress is the best blog software by many metrics. It has a good feature set, a plugin interface with lots of modules available, and the code is free. The down-side is that it’s written in PHP and has the security issues that tend to be associated with large PHP applications. Here is a good summary of the features of various blog server software [2]. One that interests me is Blojsom - a blog server written in Java [3]. The Java language was designed in a way that leads to less risk of security problems than most programming languages, as it seems unlikely that anyone will write a Blog server in Ada it seems that Java is the best option for such things. I am not planning to switch, but if I was starting from scratch I would seriously consider Blojsom. But for your first effort at blogging it might be best to start with one of the free hosted options. You can always change later on and import the old posts into your new blog. If you end up not blogging seriously then using one of the free hosted services saves you the effort of ongoing maintenance.

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Julien Danjou: Save power, aka easy CPU frequency scaling

Recently I came with the idea that my big computer is just useless. I know I was not using its entire CPU power, so I decided to take a look at CPU frequency scaling. Last time I tried, it was a PITA, required something like a daemon, and just did not work. With recent hardware and/or kernels, it's just easy as Debian. etch lenny On my box, the 3 GHz CPUs (Core 2 Duo) are running at 2 GHz (the lower value) at 99.13% of the time. That's almost a bit less power wasted.

MJ Ray: SPI Meeting Announcement and Why People Don t Join SPI

Jimmy Kaplowitz writes:
“Software in the Public Interest, Inc., will hold a public board of directors meeting on Wednesday, August 20, 2008, 19:00 UTC. [...] SPI meetings are held on the OFTC IRC network, irc.oftc.net, in #spi. [...] Agenda“
A couple of weeks ago, I asked why people do and don t join SPI? The answers I got can be grouped into a few headings:-
Don’t know about SPI
“I admit that I was unaware of SPI. However seeing its age, a few familiar names on the board and also on the project list it looks like a solid organisation.”
“I too am unfamiliar with your organization”
“I guess I would be yet aother person who was not aware of this group.”
“Lack of awareness of SPI is probably the biggest hurdle. I too, was unaware of SPI. I am aware of the Linux Foundation and the FSF and others, but how does SPI differentiate itself and its goals from those organizations?”
Don’t know about joining
“The membership page on the SPI website is buried at the bottom of a secondary menu. One has to really go looking for it. And this definitely gives the impression that adding members is not a very high priority.”
“I ve been looking a while for how to join, is not the first time, I did before and never found it until now”
Don’t see why to join
“Even as an open source software advocate, I have not joined SPI because my particular interest and focus is on Plone. The Plone Foundation handles largely the same functions that SPI does for smaller, independent groups.”
“Why, what’s in it for me? The betterment of mankind or bragging rights when a corporations steals all of my work and gets rich off of it.”
“If you are someone who is very interested FOSS (free and open source software) rights and licenses, you are probably more inclined to become a part of the FSF (Free Software Foundation) or the OSI (Open Source Initiative).”
I’d welcome any thoughts you have on how we should overcome these barriers, either in the comments here, or on IRC #spi - I think I should be there a bit before or after the meeting. I’ll try to summarise the best over the next Wednesday or two.

12 August 2008

Russell Coker: CPU vs RAM

When configuring servers the trade-offs between RAM and disk are well known. If your storage is a little slow then you can often alleviate the performance problems by installing more RAM for caching and to avoid swapping. If you have more than adequate disk IO capacity then you can over-commit memory and swap out the things that don’t get used much. One that often doesn’t get considered i the trade-off between RAM and CPU. I just migrated a server image from a machine with two P4 CPUs to a DomU on a machine with Opteron CPUs. The P4 system seemed lightly loaded (a maximum of 30% CPU time in use over any 5 minute period) so I figured that if two P4 CPUs are 30% busy then a single Opteron core should do the job. It seems that when running 32bit code, 30% of 2*3.0GHz P4 CPUs is close to the CPU power of one core of an Opteron 2352 (2.1GHz). I’m not sure whether this is due to hyper-threading actually doing some good or inefficiencies in running 32bit code on the Opteron - but the Opteron is not giving the performance I expected in this regard. Now having about 90% of the power of that CPU core in use might not be a problem, except that the load came in bursts. When a burst took the machine to 100% CPU power a server process kept forking off children to answer requests. As all the CPU power was being used it took a long time to answer queries (several seconds) so the queue started growing without end. Eventually there were enough processes running that all memory was used, the machine started thrashing, and eventually the kernel out of memory handler started killing things. I rebooted the DomU with two VCPUs (two Opteron cores) and there was no problem, performance was good, and because the load bursts last less than a minute the load average seems to stay below 1. It seems that the use of virtual machines increases the scope of this problem. The advantage of virtual machines is that you can add extra virtual hardware more easily (up to the limit of the physical hardware of course) - I could give the DomU in question 6 Opteron cores in a matter of minutes if it was necessary. The disadvantage is that the CPU use of other virtual machines can impact the operation. As there seems to be an exponential relationship between the number of CPU cores in a system and the overall price it’s not feasible to just put in 32 core Xen servers. While CPU power has generally been increasing faster than disk performance for a long time (at least the last 20 years) it seems that virtualisation provides a way of using a lot of that CPU power. It is possible to have a 1:1 mapping of real CPUs and VCPUs in the Xen DomU’s, if you were to install 8 DomU’s that each had one VCPU on a server with 8 cores then there would be no competition between DomUs for CPU time - but that would significantly increase the cost of running them (some ISPs offer this for a premium price). In this example, if I had a burst of load for the service in question at the same time as other DomUs were using a lot of CPU time (which is a possibility as the other DomUs are the clients for the service in question) then I might end up with the same problem in spite of having assigned two VCPUs to the DomU. The real solution is to configure the server to limit the number of children that it forks off, the limit can be high enough to guarantee 100% CPU use at times of peak load without being high enough to start swapping. I wonder how this goes with ISPs that offer Xen hosting. It seems that you would only need to have one customer who shares the same Xen server as you experiencing such a situation to cause enough disk IO to cripple the performance that you get.

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David Welton: Hecl Syntax: A Survey

[ Taken and modified from a post to the hecl-devel mailing list ] I've been talking with a company about a consulting job regarding a programming language for mobile apps. Sounds familiar, right? There is, however, a bit of discussion regarding the syntax - my contact at said company maintains that Hecl's syntax is unfamiliar to many programmers, and I think on the face of it, I'd have to agree. Of course, Hecl's syntax is like it is because when I started the project, being very small was a necessity, and a very simple syntax facilitated that goal nicely. Additionally, the syntax allows for extreme flexibility, letting you create new control commands, and "DSL's" (domain specific languages) easily. Also, sticking with small/simple means that the interpreter and parser can both reside on the phone, instead of doing some kind of solution where the development/host computer compiles the scripting language to byte code, and the interpreter on the phone runs the byte code. That sort of strategy has some advantages, but has disadvantages too: if you don't have an on-board parser, you don't get "eval".
A quick Hecl syntax refresher: In Hecl, everything is a command, seperated by spaces, and grouped with : 
if   ...     ...
Is a command that takes two arguments. It evaluates the first one, and if it's true, evaluates the second one. This is different from languages like C, Python or Ruby, where 'if' is part of the language. For those unfamiliar with languages like Lisp, where this looks strangest is probably in conditions or other expressions: 
if   = $foo 10     puts "foo is ten"
Or 
set foo [+ [* $bar 10] [- $beebop $doowah]]
Which is certainly a different take on things than most 'mainstream' languages. That radical simplification is, however, one of the ways that I used to save space in the interpreter.
Personally, I'm pretty happy with how Hecl looks, but I am sensitive to the 'marketing' argument: popularity helps, and this isn't the first time I've heard complaints about Hecl looking "funny" to people. What do you think? A) "I like Hecl just the way it is and wouldn't want to change it!" B) "Hecl is quite useful, but I just want a mobile scripting language, the syntax doesn't matter much." C) "I think the syntax is ugly, but I use it because I need an interpreter." Also related: 1) "I don't care too much about code size. My current apps target N kb as an acceptable size." 2) "Small is really important. The smaller the better." And: I) "I don't care about eval, or being able to run human readable code on the phone." II) "I really like the fact that you can download or even write code directly on the phone." And finally: X) "I don't care about midp1.0" Y) "The fact that Hecl runs on midp1.0/cldc1.0 is important to me." Now, I am not going to run off and change Hecl! Code that currently runs ought to continue to run, modulo some tweaks here and there, api changes, and the normal stuff. If I do something 'new', it would probably be a clean break (although of course code that could be reused would be), and will be in addition to Hecl, rather than instead of Hecl, because I would be working on the 'new' language as a day job. I do that with Hecl too, but not all the time, as I often have consulting/contracting work.

MJ Ray: DebConf 8 Video Team Gives Excellent Service

DebConf, the annual Debian Conference, is held this year in Mar del Plata, Argentina. One sometimes-overlooked part of this is the brilliant video streaming service, with each stream supported by an IRC feedback channel including announcement of talks and events as they approach, start and finish. While I was watching Martin F. Krafft’s talk yesterday (which introduced the topgit patch manager to me, which I’ll look at and may suggest to the Koha project), I was blown away by the production quality of the video. It’s even better than last year, which was already good. The shots of the slides with the presenter in a little window on them are a particularly clever idea and much better than the “auto-refreshing slides webpage” method I’ve seen from other conferences. It does look like a little encoder tweaking might be possible to get the slides (which don’t change much) pixel-perfect while compressing the presenter window, but I’d be happy if all conferences were covered this well. Read the debconf announcement for links to the streams and schedules. I was having a few problems watching this afternoon (packets getting lost between telecomplete and bytemark), but switching to a European video server helped it. Mplayer’s hardframedrop also seems to help in bad network conditions, but it takes multiple attempts to get a successful connection from mplayer, for reasons I don’t understand. The conference continues until next weekend, which includes Debian’s 15th anniversary.

Joerg Jaspert: DebConf8 - And time after it

Third day of DebConf8 now - and it has been a pretty nice time since I arrived. The local orga team is doing a marvelous job, making this whole conference a really nice experience for about every attendee. Thanks to that we had a lot of time doing actual Debian work, which meant that we got a nice number of changes in dak either done or planned for the future, including a redesign of our database schema. Which is urgently needed if we want to follow some of the points we discussed. Like throwing away apt-ftparchive and generating the Packages files ourselve. Or various other enhancements. So for dak, the changes are summarised into: But we did not only do work on dak, we also did some work for the conference. In the days down here we (re)wrote the Pentabarf entrance controller, enabling our frontdesk to check people in, keeping track of various details they need to know about them. We wrote entirely new controllers for Pentabarf, one of it being the part that manages this years Assassins game. Other orga team members (hello triple des :) ) wrote a video and a volunteer controller. I guess after DebConf we will have some fun time to merge our changes back to upstream.
Travel in .ar Oh well, as some people know, I stay in Argentina for about 10 days more after DebConf is over (my flight back goes on 27. August, in the evening). Up to now I haven’t decided - or even started planning - what I do here. I should probably look at that soon. Hrm. Anyone out there doing something similar the next days? :) Comments: 0

Russell Coker: SpamAssassin During SMTP

For some time people have been telling me about the benefits of SpamAssassin (SA). I have installed it once for a client (at their demand and against my recommendation) but was not satisfied with the result (managing the spam folder was too complex for their users). The typical configuration of SA has it run after mail has been accepted by the server. Messages that it regards as spam are put into a spam folder. This means that when someone phones you about some important message you didn’t receive then you have to check that folder. Someone who sends mail to a user who has such a SA configuration can not expect that the message will either be received or rejected (thus giving them a bounce message). Even worse it seems to be quite common for technical users to train the Bayesian part of SA on messages from the spam folder - without reviewing them! Submitting a folder of spam that has been carefully reviewed for Bayesian training can increase the accuracy of classification (including taking account for locality and language differences in spam). Submitting a folder which is not reviewed means that when a false-positive gets into that folder (which will eventually happen) it is used as training for spam recognition thus increasing the incidence of false-positives! Spam has been becoming more of a problem for me recently, on a typical day between 20 and 40 spam messages would get past the array of DNSBL services I use and be re-sent to pass the grey-listing. Also I have been receiving complaints from people who want to send email to me about some of the DNSBL and RHSBL services I use (the rfc-ignorant.org service gets a lot of complaints - there are a huge number of ignorant and lazy people running mail servers). So now I have installed spamassassin-milter to have SA run during the SMTP protocol. Then if SA checks indicate that the message is SPAM my mail server can just reject the message with a 55x which will cause the sending mail server to generate a local bounce (if it’s a legitimate message) or to just be discard it in the case of a spam server. Here is how to set it up on Debian/Lenny and CentOS 5: Install the package yum install spamass-milter or apt-get install spamass-milter spamassassin spamc (spamassassin seems to be installed by default on CentOS). On a Debian system the milter will be setup and running. On CentOS you have to run the following commands:
useradd -m -c "Spamassassin Milter" -s /bin/false spamass-milter
mkdir /var/run/spamass-milter
chown spamass-milter /var/run/spamass-milter
chmod 711 /var/run/spamass-milter
echo SOCKET="/var/run/spamass-milter/spamass.sock" >> /etc/sysconfig/spamass-milter On CentOS edit /etc/init.d/spamass-milter and change the daemon start line to ‘runuser - spamass-milter -s /bin/bash -c "/usr/sbin/spamass-milter -p $SOCKET -f $EXTRA_FLAGS"‘ Then add the following lines below it:
chown postfix:postfix /var/run/spamass-milter/spamass.sock
chmod 660 /var/run/spamass-milter/spamass.sock The spamass-milter program talks to the SpamAssassin daemon spamd. On both Debian and CentOS run the command “useradd -c Spamassassin -m -s /bin/false spamassassin” to create an account for SA. The Debian bug #486914 [1] has a request to have SA not run as root by default. On CentOS it seems that SA wants to use a directory under the spamass-milter home directory, the following commands alllow this. It would be good to have it not do that, or maybe it would be better to have the one Unix account used for SA and the milter.
chmod 711 ~spamass-milter
mkdir ~spamassassin/.spamassassin
chown spamassassin ~spamassassin/.spamassassin On Debian edit the file /etc/default/spamassassin and add “-u spamassassin -g spamassassin” to the OPTIONS line. On CentOS edit the file /etc/sysconfig/spamassassin and add “-u spamassassin -g spamassassin” to the SPAMDOPTIONS line. To enable the daemons, on CentOS you need to run “chkconfig spamass-milter on ; chkconfig spamassassin on“, on Debian edit the file /etc/default/spamassassin and set ENABLED=1. Now start the daemons, on CentOS use the command “service spamassassin start ; service spamass-milter start“, on Debian use the command “/etc/init.d/spamassassin start“. Now you have to edit the mail server configuration, for Postfix on CentOS the command “postconf -e smtpd_milters=unix:/var/run/spamass-milter/spamass.sock” will do it, for Postfix on Debian the command “postconf -e smtpd_milters=unix:/var/spool/postfix/spamass/spamass.sock” will do it. Now restart Postfix and it should be working. For correct operation you need to ensure that the score needed for a bounce is specified as the same number in both the spamass-milter and SA configuration. If you have a lower number for the spamass-milter configuration (as is the default in Debian) then bounces can be generated - you should never generate a bounce for a spam. The config file /etc/default/spamass-milter allows you to specify the score for rejecting mail, I am currently using a score of 5. Any changes to the score need matching changes to /etc/mail/spamassassin/local.cf (which has a default required_score of 5 in Debian). You can grep for “spamd..result..Y” in your mail log to see entries for messages that were rejected. One problem that I have with this configuration on Debian (not on CentOS) is that spamd is logging messages such as “spamd: handle_user unable to find user: ‘russell’“. I don’t want it to look for ~russell when processing mail for russell@coker.com.au because I have a virtual domain set up and the delivery mailbox has a different name. Ideally I could configure it to know the mapping between users and mailboxes (maybe by parsing the /etc/postfix/virtual.db file). But having it simply not attempt to access per-user configuration would be good too. Any suggestions would be appreciated. Now that I have SpamAssassin running it seems that I am getting about 5 spams a day, the difference is significant. The next thing I will do is make some of the DNSBL checks that are prone to false-positives become SpamAssassin scores instead. When I started writing this post I was not planning to compare the sys-admin experiences of CentOS and Debian. But it does seem that there is less work involved in the task of installing Debian packages.

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MJ Ray: Don t Attack Your Users

It seems to me like basic business common sense not to attack your software’s users, because they’re people who might fund your future development work, when they want some new feature adding or some adaptation making. We should hope that this audience will become co-promoters, co-developers or co-producers of free and open source software in the future. Indeed, one of the basic lessons at our webmaster cooperative is to try to direct enquiries about software we’ve co-produced to somewhere useful, even if the question isn’t really much to do with us (because it’s about some part we didn’t produce or it’s something we’re no longer funded to work on), or even if we suspect the questioner has done something very silly. This approach has worked well so far. So, just don’t attack your users. It’s not on. Don’t do it. This basic lesson of not attacking users doesn’t seem to have been learned in software industries in general. Most software comes with a very restrictive “End User License Agreement” that seems to treat the user as if they are a potential criminal and grabs as many rights as possible for the software producer. I expect that Microsoft’s new post-Windows operating system will continue this approach and that the user-tracking possibilities of internet-centred operation will be exploited as far as legally possible. Hopefully, we’ll continue to see pre-installed Linux growing strongly in UK as Bristol Wireless describe. However, this pales into insignificance compared to many media companies. One of the worst offenders is Bristol-based TV Licensing who send us a “pay up or else, you potential criminal”-style letter each year. If there’s ever a reform that makes BBC subscription voluntary, they will probably reap the seeds of hatred that TVL have sown by attacking their audience. I have quite a lot of admiration for people like Martyn Drake who are fighting a noble fight in things like TV Licensing - the war begins! but I wonder whether media companies will learn not to attack their users before they cease to exist.

11 August 2008

Andrew Pollock: [tech] Amanda, tar, and Debian Etch

Somehow (thankfully) I've managed to avoid much to do with backups in my career as a sysadmin. It's always been someone else's responsibility, that's been fine by me. For some reason, I've been more paranoid lately, and with all of the crazy shit I've been doing to daedalus, I wanted to have a backup, just in case. Maybe it's old age. So a while ago, I went and had a stab at setting up Amanda, since pretty much whenever I've been near a bunch of sysadmins and someone asks for a recommendation on what to use, "Amanda" is the answer. I jumped through all of the hoops to have caesar be the backup server, and daedalus be a client. I set up a virtual tape library on caesar. I think I then lost interest for a while, until I was going to upgrade daedalus to Etch, and I wanted to have a successful backup first. I had the holding disk and the virtual tape library on the same filesystem, and it was nice and big, yet I kept running into this error about insufficient space. "dump larger than available tape space" was the complaint. I tried making the filesystem larger. I tried adding more virtual tapes. Nothing would placate it. After another round of Googling, I discovered that the problem was because Amanda would only only span a maximum of four tapes, and the filesystem I was trying to backup was way bigger than that. So I told it to use up to 10 tapes in a run (runtapes 10) and then lo and behold, I got a successful backup out of the sucker. So that was mostly all good, but occasionally a backup would fail, or fail once an succeed on a retry, because tar exited non-zero, with "file changed as we read it". I did some more Googling tonight, and discovered this Amanda/GNU tar compatibility matrix. It turns out that the version of tar and the version of Amanda shipped in Debian Etch aren't compatible with each other. Suck! Oh wait, they're maintained by the same person! Argh! So aside from the occasional backup failing due to a file being written to at the time of the backup, it's working fairly well. My DSL link isn't the fastest, so a full backup of daedalus can take over 48 hours to complete, but I'm not paying for inbound bandwidth at home, so it's not a big deal. I initially thought that to do a restore, I'd have to run amrecover on daedalus, and then I'd have to stream the contents of multiple tapes back to it at the appalling uplink speed of my DSL connection, but fortunately amrecover has a sethost command, so I can restore just the files I need on another machine local to caesar at LAN speeds, and just transfer the files I restore to daedalus. So that's all pretty neat. I quite like the FTP-client-like interface of amrecover. It's cool how you can use setdate and just go back in time. I had the opportunity to do a test restore recently when one of my users nuked his Maildir directory by accident. Unfortunately I was unable to recover the needed files in that case, and I'm not entirely sure what the problem was, so there's some more testing to be done before I'll be fully confident that I can rely on it. There's a lot of configuration options available as well, and I think I got the config I'm currently using from a template or something, so there's probably a fair bit of tweaking I can do. Oh, and I'm constantly reminded of this quote from a previous life, where technical details bubbled too far up non-technical management:
"Who is Amanda, and what is her role in the backups?"

Michael Banck: 11 Aug 2008

OpenSync update To give some update on the state of OpenSync in Debian, I have uploaded libsycml-0.4.7 to experimental a couple of days ago. This is significant in sofar as a lot of development and bug-fixing (mostly by Michael Bell) happened for this release, as well as some committment to maintaining an API and at least responsively versioning the library. In order to use libsyncml-0.4.7 with OpenSync, a newer libopensync than 0.36 is needed; however, current OpenSync trunk has seen a lot of changes in plugin handling and plugins need to get ported to the new API. So I uploaded the last known-working revision of OpenSync along with corresponing revisions of the file-sync and syncml plugins, the vformat module and a rebuild of msynctool to experimental for now. I did not have the time or energy to migrate/upload the other plugins yet, and as it seems that OpenSync-0.37 will only ship with ported file-sync and syncml plugins, it might not make much sense. I also took over maintainership of the related wbxml2 package, and upload a patch by Michael Bell which seem to fix a lot issues people are having with SyncML. The good news is that it seems all of the new features for a 0.40 stable OpenSync release have been finished according to the roadmap , most notably a common plugin configuration system and the machinery for a migration path from 0.22 to 0.40 configurations (plugins still need to support/implement that I believe), so no more big API changes are expected and the focus will be on bugfixing and plugin discovery from now on. This means developers will be able to start porting their plugins to the 0.40 API once 0.37 is out and front-end authors can start to take a look at the architectural changes which were made to facilitate their jobs. My hope is that conduit will be able to leverage the OpenSync technology and introduce a solid GUI for this (as kitchensync does for KDE), making syncronization finally work on the desktops. From the Debian packaging point of view, I have been mostly on my own now for the last couple of months. However, I recently registered an Alioth project in order to maintain the packages in a subversion repository (I have not yet decided whether it is worth importing the 0.22 packages targetted at lenny), and people who are interested in helping should contact me.

Antti-Juhani Kaijanaho: Velisurmaaja The Brother Slayer

Velisurmaaja was published in Elias L nnrot’s collection of traditional Finnish poems, the Kanteletar in 1840. It bears some similarity to the British ballad Edward. What follows is the original text, lifted from the tenth Gutenberg edition of Kanteletar juxtaposed with my English translation (which is more concerned with getting the message across than being good poetry). However, I am assured the translation is not beyond redemption, so here it is: (more…)

Russell Coker: Compassion for Windows Users

In a discussion which covered some of the differences between Linux and Windows, a Windows using friend asked me if I felt compassion for Windows users. I feel some compassion for people who have bad working environments. While using an operating system that has poor support for the business tasks does decrease the quality of the working environment, there are bigger issues. For example a while ago I was doing some sys-admin work for a financial organisation. I had to use Windows for running the SSH client to connect to Linux servers, this was annoying and decreased my productivity due to the inability to script connections etc. My productivity was also decreased because of my unfamiliarity with the Windows environment, it seems reasonable to assume that when you hire a Linux sys-admin they will have some experience of Linux on the desktop and be quite productive with a Linux desktop system - while the same can not be said for a Windows desktop. But what really made the working environment awful was the paperwork and the procedures. If a server doesn’t work properly and someone says “please fix it now” and I only have a VT100 terminal then I’ll be reasonably happy with that work environment (really - I wouldn’t mind a contract where the only thing on my desk was a VT100 connected to a Linux server). But when a server process hangs in the same way several times a week, when the cause of the problem is known and the fix (restarting the process) is known it really pains me to have to wait for a management discussion about the scope of the problem before restarting it. But I don’t have a great deal of sympathy for people who end up in bad working environments such as the one I was briefly in. Anyone who is capable of getting such a job is capable of getting a job with a better working environment while still earning significantly more than the median income. The people I feel sorry for are the ones who work on the minimum wage. I don’t think that the difference between Linux and Windows on the desktop would matter much if you were getting the minimum wage, and people who are on the minimum wage don’t have a lot of choice in regard to employment (I think that all options for them suck). I don’t have much sympathy for adults who use Windows at home. I have to admit that there are some benefits to running Windows at home, mainly that the hardware vendors support it better (few companies sell PCs with Linux pre-loaded) and there are some commercial games which are in some ways better than the free games (of course there are more than enough free Linux games to waste all your time - and some games are best suited to a console). Linux has significantly lower hardware requirements than Windows (my main machine which I am using to write this blog post is more than three years old and has less power than any other machine on sale today apart from some ultra-mobile PCs), so any long-term Windows user can install Linux on one of their machines which lacks the resources to run the latest version of Windows. The only Windows users for whom I have much sympathy are children. When I was young every PC came with a BASIC interpreter and everyone shared source code. Books were published which taught children how to program in BASIC which included fairly complete example programs. For the cases where proprietary software was needed the prices used to be quite low (admittedly the programs were much less complex - so pricing is probably in line with the effort or writing the code). Now it seems that computers are often being provided to children as closed systems that they can’t manipulate, the web browser has replaced the TV. I believe that Linux is the ideal OS for a child to use. There is a wide range of free educational programs (including kturtle - the traditional Logo turtle) and there are also a range of free powerful programs which can be used by any child. Few parents would buy Photoshop or Adobe Illustrator for a child to play with, but anyone can give a child a $100 PC with GIMP and Inkscape installed. They might as well give 3yo children access to the GIMP - it will be less messy than fingerpainting! I expect that some parents would not consider Linux for their children because they don’t know how to use it. Fortunately Linux is easy enough to use that a child can install it without effort. Some time ago the 11yo daughter of a friend who was visiting asked if she could play some computer games. I gave her a Fedora CD and one of the PCs from my test lab and told her that she had to install the OS first. Within a small amount of time she had Fedora installed and was playing games. While the games she played were not particularly educational, the fact that she could install the OS on a computer was a useful lesson. It seems to me that children who are raised as Windows users are less likely to learn how computers work or be able to control them properly. I expect that on average a child who is raised in such a manner will have fewer career options in today’s environment than one who properly understands and controls computers.

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Peter Van Eynde: encrypted root filesystems on servers

The one problem I have with my server at home now seems to have a fix.

The server has a standard encrypted root, as configured by debian-installer. The issue with this is that after booting I need to go to the console and enter the LUKS password. As I do almost everything remotely this is a pain.

However C'T published a nice article a while ago on how to solve this. The short story is that you install a custom initrd plugin that starts dropbear and waits for the password on the console or via ssh.

Now to install and test this...

10 August 2008

Alexander Reichle-Schmehl: Bits from the DPN editors

It's more or less four months since I proposed to resurrect our newsletter. We already released eight issues of the Debian Project News and work for the ninth issue has already started. So I guess it's time for a small "state of the DPN" speech, but since I'm not attending DebConf, you will have to read this mail instead ;) After having a rough start (and in fact missing some self-set deadlines and completely underestimating how much work is involved in such a kind of newsletter) we finally developed a - more or less - working flow of work (Which is by the way documented here). Speaking of the current state sadly means to confess, that our hopes to draw a lot of help from the community by using a system for drafting the news with a low entry barrier were not fulfilled. We actually had a good start, with good participation, but due to (I assume) the aforementioned initial difficulties participation in the creation of the DPN dropped considerably. Currently the workload of creating our bi-weekly newsletter is shared by only two people (that being Meike Reichle and myself), which is barely enough :( While we at least get a hint from time to time, what we should mention in the next issue, it rarely happens, that someone contributes by drafting a text -- which is the real work. (At this point a BIG "Thank You" to those who did! (See list bellow.) It's much appreciated!) We suffer especially, since although we are a two people team, we have in fact no redundancy, since real live issues affecting one of us will most likely affect the other one, too. Therefore we mostly concentrated our work on creating the next issues and getting them out in time, and didn't have time to answer all mails considering suggestions for changes and improvements (yet?). We are sorry, but at least we tried to read them briefly and keep them in mind when drafting the next issue. As a result of this we re-added the list of DSAs, WNPP and new and noteworthy packages due to popular demand. There are still a lot of unanswered mails not dealing with content, but with workflow issues / proposals (including changing from wiki.debian.org to a special ikiwiki instance). We are sorry, that we couldn't yet act on them and take appropriate measures, but be assured, they are not forgotten. Other issues the DPN currently have are "unwritten guidelines" regarding editorial choices of DSAs to be published and which packages to list in the "new and noteworthy package" section. Both is more or less done by our gut feeling. Speaking of problems the DPN are facing, we also need to mention translations of the DPN. The current workflow makes it difficult for translators of the DPN, since we often fail to get the final draft of the DPN ready in time to give translators a "head start" so the translated DPNs can be released together with (or at least with a as small as possible delay to) the English DPN. So here is a big call for help! We really need your help writing the DPN. (Monitoring lists and newstickers we don't monitor ourselves would be nice, too, but only add more work to us if you only give us pointers.) We will both be very busy with our real live the upcoming month, and are not sure how much time we can dedicate to the DPN. So please help us! The current draft for the next issue of the DPN is always available here . There should already be a todo list with pointers to interesting topics, which need to be written out. Some guidelines about style and content are available here. Last but not least, we would like to thank the following people who have contributed to the DPN so far: (Unfortunately we can't list those people, who contributed by translating the DPN, nor do we have a complete list of the native English speakers, who helped by proofreading. But we thank them nonetheless!)

Clint Adams: Esperando por Andrew

Things I am not going to do this week:

Joerg Jaspert: DebConf Assassins

Today is the day we start this years Assassins game, and I (together with the two other DebConf admins Mark and Stephen) have the role of the referee. As we all don’t want to do it by hand, and have seen bad examples in the past where the referee just wasn’t up to the task, we go another way. In the last two days, Stephen and me (mostly Stephen) developed a Pentabarf controller to do the work for us. It is ready for the game, so we start today. This controller basically tells the players their target, gets the “I killed em” notice and lets the target confirm it, then assigning a new target. And when we are done with the game - it even tells us the winner and also some information about the other players. This controller made us able to do another change to the known game rules: People can enter the game when it is already running. Which is useful, as now we only let people play that arrived at the venue. Late-comers get added to the players list whenever someone got killed. This ensures that no assassin has to wait for half the Conference time until their target finally arrives! (Ok, it might mean that Late-Comers have to wait a day or two before they finally get a target, as we only insert new players when someone dies). One more note if you are playing: Don’t tell anyone, not even your assassin, your target. Your assassin might not neccessarily get your target as his next (if we add people to the set), so keep it secret, all the time. The only people you should talk to about this game are us 3 admins, but only in case you have a problem. :) Comments: 0

Russell Coker: Xen CPU use per Domain

The command “xm list” displays the number of seconds of CPU time used by each Xen domain. This makes it easy to compare the CPU use of the various domains if they were all started at the same time (usually system boot). But is not very helpful if they were started at different times. I wrote a little Perl program to display the percentage of one CPU that has been used by each domain, here is a sample of the output: Domain-0 uses 7.70% of one CPU
demo uses 0.06% of one CPU
lenny32 uses 2.07% of one CPU
unstable uses 0.30% of one CPU Now the command “xm top” can give you the amount of CPU time used at any moment (which is very useful). But it’s also good to be able to see how much is being used over the course of some days of operation. For example if a domain is using the equivalent of 34% of one CPU over the course of a week (as one domain that I run is doing) then it makes sense to allocate more than one VCPU to it so that things don’t slow down at peak times or when cron jobs are running. I believe that it’s best to limit the number of CPUs allocated to Xen domains. For example I am running a Xen server with 8 CPU cores. I could grant each domain access to 8 VCPUs, but then any domain could use all that CPU power if it ran wild. While if I give no domain more than 2 VCPUs then one domain could use all the CPU resources allocated to it without the other domains being impacted. I realise that there are scheduling algorithms in the Xen kernel that are designed to deal with such situations, but I believe that simply denying access to excessive resource use is more effective and reliable. I have not filed a bug report requesting that my script be added to one of the Xen packages as I’m not sure which one it would belong in (and also it’s a bit of a hack). It’s licensed under the GPL so anyone who wants to use it can do what they want. Any distribution package maintainer who wants to include it in a Xen utilities package is welcome to do so. The code is below.
#!/usr/bin/perl
use strict; open(LIST, "xm list --long ") or die "Can't get list"; my $name = "Dom0";
my $uptime = 0.0;
my $cpu_time = 0.0; open(UPTIME, "</proc/uptime") or die "Can't open /proc/uptime";
my @arr = split(/ /, <UPTIME>);
$uptime = $arr[0];
close(UPTIME); while(<LIST>)

  chomp;
  if($_ =~ /^\)/)
 
    my $cpu = $cpu_time / $uptime * 100.0;
    printf("%s uses %.2f%% of one CPU\n", $name, $cpu);
    next;
 
  $_ =~ s/\).*$//;
  if($_ =~ /up_time /)
 
    $_ =~ s/^.*up_time //;
    $uptime = $_;
    next;
 
  if($_ =~ /cpu_time /)
 
    $_ =~ s/^.*cpu_time //;
    $cpu_time = $_;
    next;
 
  if($_ =~ /\(name /)
 
    $_ =~ s/^.*name //;
    $name = $_;
    next;
 

close(LIST);

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