Monthly Archive for November, 2008

Cambridge Mirror Fun

Published on November 26, 2008 in fedora and mirror server. 0 Comments

New Fedora releases are always great because they are one of the few times in the year at which our mirror server really has something to do. And I really like to watch all our little statistics. So instead of the usual 2-3TB we are pushing out each day we pushed almost 5TB on the release day and the release happened not before 1600. So I expect that that number will be even higher tomorrow.

The bandwidth graph generated by munin:

Cambridge Release

And the mirror traffic breakdown from the release day:

Mirror Traffic Breakdown 2008-11-25

During the eight hours at which Fedora 10 was available from our mirror server on the release day we transmitted 2.23TB Fedora related data.

Bratapfelkonfitüre

Published on November 21, 2008 in rezepte. 0 Comments
  • 50g Rosinen (über Nacht mit Rum marinieren)
  • 3EL Rum (ersatzweise Apfelsaft)
  • 30g gehobelte Mandeln
  • 1kg Äpfel (z.B. Delicious)
  • 1 Päckchen Vanille-Zucker
  • 1TL gemahlener Zimt
  • 1 Päckchen Zitronensäure
  • 500g Gelierzucker 2:1
  • 1 Beutel Gelfix extra (25g)

Rosinen mit Rum tränken und über Nacht ziehen lassen.

Mandeln in einer beschichteten Pfanne ohne Fett goldbraun rösten. Äpfel schälen, halbieren, entkernen und in kleine Würfel schneiden.

Äpfel, Rosinen, Mandeln, Vanille-Zucker, Zimt und Zitronensäure in einen großen Topf geben und etwa 5 Minuten weich dünsten.

Zucker und Gelfix mischen und mit der Fruchtmasse verrühren. Bei starker Hitze zum Kochen bringen; mindestens 3 Minuten unter Rühren kochen lassen.

Fruchtmasse in vorbereitete, heiß ausgespülte Gläser füllen und dann verschließen. Gläser auf den Kopf drehen und abkühlen lassen.

Haltbarkeit: ungefähr 6 Monate

Kover 4

Published on November 21, 2008 in free software. 1 Comment Tags: .

I finally finished porting kover to KDE4. I also changed it to use cmake.  There are not really any new features, but the porting to KDE4 was in large parts a complete rewrite. Some parts of the code were still using functions which were deprecated since QT2 and so I had a chance to do a big cleanup of the code while porting it to KDE4. It is still the same application with the same user interface and I probably also ported all the bugs it has.

It can be downloaded from http://lisas.de/kover/download.php3 or using git from http://lisas.de/kover/git.

Update: I just discovered that there is review on linux.com about the previous version of kover (kover-3).

MirrorManager In RPM Fusion

Published on November 20, 2008 in fedora. 2 Comments Tags: , .

RPM Fusion now also has a MirrorManager instance running. I have written some minimal documentation about RPM Fusion’s MirrorManager setup but it is pretty much the same as already documented for Fedora. It took me a few days to understand how all the different parts of the MirrorManager are working together, but I think I have now a pretty good overview how it all works. Matt has really written a nice piece of software and he accepted all my patches. My patches were mostly getting rid of hardcoded Fedora URLs and putting Fedora specific stuff in configuration files.

The public mirror list can be accessed here: http://mirrors.rpmfusion.org/mm/publiclist/

The mirrorlist which is generated for yum can be accessed here: http://mirrors.rpmfusion.org/mirrorlist?…

To provide at least some kind of “high” availability mirrors.rpmfusion.org consists of two hosts. One is run by me and the other is provided by Oliver.

The MirrorManager database web interface is running at https://lisas.de/mm/. The reason for not running it under the rpmfusion.org domain was that I have signed SSL certificate for lisas.de and because it transmits a user name and password I wanted it to run over an encrypted connection. But as only mirror admins have to use that interface it should cause not too much confusion for the users of RPM Fusion.

I am using the information from the mirrorlist accesses to generate some statistics about the countries where RPM Fusion is used as well as statistics about the usage of the repositories and architectures: http://mirrors.rpmfusion.org/statistics/

Weihnachtsmarmelade

Published on November 20, 2008 in rezepte. 0 Comments
  • 500g gewürfelte säuerliche Äpfel
  • 300 ml Rotwein
  • Saft einer Orange (ca. 100ml)
  • 2 Nelken
  • ½ Teelöffel Zimt
  • 500g Gelierzucker 2:1
  • 2 Esslöffel Mandelblätter
  • 2 Esslöffel Rosinen

Rotwein in einen großen Topf geben und alle Zutaten, jedoch ohne die Äpfel, einrühren. Am Besten einige Zeit ziehen lassen.

Die geschälten und entkernten Äpfel würfeln (ca. 1cm Würfel). Die Äpfel in das durchgezogene Gemisch geben und zum Kochen bringen. 3 Minuten kochen. Fertig.

Statt Rotwein kann man auch Weißwein nehmen.

Evacuation!

Published on November 13, 2008 in adrian. 0 Comments Tags: .

The block where I live has a small combined heat and power plant. It is mainly used to provide all the houses with hot water which is used for heating. It is supposed to be very ecological. But today it was on fire. The whole thing was burning; not just on the inside (like it is supposed to be) but also on the outside.

A lot of firefighters arrived and just a bit later the police told everybody that we have to leave our houses because there was a chance of an explosion.

So I left the house, called a few people and waited in a small cafe until I could return back home. About an hour later we were informed that we can return to our houses.

When I returned back home there was no more smoke observable.

The big question now is if our heating, which is run by that power plant, will continue to work and if my car (if you know where it is it can be seen on the pictures) which is parked right next to the plant has survived without any damage.

Which Filesystem? EXT3, Of Course!

Published on November 11, 2008 in mirror server. 2 Comments Tags: .

I recently asked Which Filesystem should I use for my new 10TB partition. Thanks for all the comments and I want to answer a few of them.

There were a few recommendations (1, 2) to use XFS. I hear it a lot, but unfortunately it has never been as stable as EXT3 when I tried to use it in the past. It is important to remember that I am running it on a mirror server and after all the years maintaining our mirror server I have learned that the load which is generated by around 1500 users accessing different files at the same time is really different to anything else. I need to have a filesystem which is always stable and in my experience this is only fulfilled by EXT3. Because if something breaks I have so much data, that I cannot make a backup and restore it.

The other reason to not use XFS is that I am running a CentOS kernel and XFS support is only available through kmod-xfs and I have no idea how well maintained it is and if somebody is backporting all the important bugfixes to 2.6.18 (the CentOS kernel version).

Somebody said I should use ZFS and mount it via NFS. I was so happy a few years ago to get rid of NFS in our mirror server setup and I really do not want to have it back. I do not know if other mirrors are using NFS, but it never was any good in our setup. Currently we are using iSCSI if we have to mount something from a remote host. It works pretty good but does not help here because I would still have to create the filesystem locally.

I was happy to hear that Fedora infrastructure uses 10TB partitions with EXT3 (3, 4) and that was exactly the information I wanted to hear.

I have now created a 10TB partition using mke2fs -F -j /dev/sdf1 and it only took about 18 hours ;-) . The RAID is still initializing in the background which makes all accesses a bit slower.

It is now mounted any I am starting to sync the data from the temporary iSCSI volume back to the new RAID:

/dev/sdf1             9.0T   26G  9.0T   1% /ftp/pub/.3

I have also benchmarked it with bonnie++ (bonnie++ -d bonnie -s 80g -m rhlx01 -u 123 -g 321), once with the background initializing still running:

Version  1.03       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
rhlx01          80G 40390  92 62845  30 17201   4 27259  43 31459   3  98.5   0

and once in a completely initialized state:

Version  1.03       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
rhlx01          80G 44377  96 95589  40 36061   7 32464  51 70583   7 242.7   0

Those values are pretty much the same as with the old RAID.

Which Filesystem?

Published on November 10, 2008 in mirror server. 10 Comments Tags: .

Right now I am preparing the new RAID array for our mirror server. It is a Fibre Channel connected external box with 12 1TB drives. It will offer around 10TB of space for our mirror server. That sounds like it will be enough for the next few years. But new RAIDs always tend to have a lot of space and after 6 months or so they usually start to get full.

So I was planning on using ext3, because that is just the most stable filesystem for our mirror server scenario. I tried all of the other filesystems and at one point they all were not stable enough and then I switched back to ext3.

Unfortunately it seems like ext3 does not support filesystems larger than 8TB, and for our mirror server scenario I would prefer to have one big partition instead of two (or even more) partitions. To partition it I had to use again parted like I did last time because fdisk cannot handle partitions larger than 2TB.

I am running a CentOS kernel and I read that, although mke2fs prints out a warning, if using the parameter to force the file system creation (-F) it is actually possible to create ext3 filesystems with up to 16TB.

So using mke2fs -F -j /dev/sdf1 I was able to create a 10TB filesystem and mount it.

Given the fact the mke2fs warns about creating filesystems larger than 8TB is not possible and that it only works if it is forced, I am not sure if using an ext3 filesystem larger than 8TB is such a well tested feature. So I am not sure if I should rather create two partitions or one large 10TB partition.

Oh, and the reason I rather want to a have single partition is that I want to be able to use hardlinks as much as possible to save space.

This Is The End

Published on November 3, 2008 in adrian and free software. 1 Comment

Today is my first day not working for IBM since the last four years. Exactly two weeks ago (2008-10-20) all contractors (that includes me) were told that they had been laid off. We were told that this was happening world wide.

Last Wednesday (2008-10-29) was my last day in the office and the last four days I was snowboarding in Sölden.

It was a great time working at IBM and I met really nice people there.

I am now looking for a new job and have already started to get in contact with some people to talk about possible new projects. If somebody knows a free software job… Let me know.