Search Results: "Benjamin Drung"

16 November 2023

Dimitri John Ledkov: Ubuntu 23.10 significantly reduces the installed kernel footprint

Photo by Pixabay
Ubuntu systems typically have up to 3 kernels installed, before they are auto-removed by apt on classic installs. Historically the installation was optimized for metered download size only. However, kernel size growth and usage no longer warrant such optimizations. During the 23.10 Mantic Minatour cycle, I led a coordinated effort across multiple teams to implement lots of optimizations that together achieved unprecedented install footprint improvements.

Given a typical install of 3 generic kernel ABIs in the default configuration on a regular-sized VM (2 CPU cores 8GB of RAM) the following metrics are achieved in Ubuntu 23.10 versus Ubuntu 22.04 LTS:

  • 2x less disk space used (1,417MB vs 2,940MB, including initrd)

  • 3x less peak RAM usage for the initrd boot (68MB vs 204MB)

  • 0.5x increase in download size (949MB vs 600MB)

  • 2.5x faster initrd generation (4.5s vs 11.3s)

  • approximately the same total time (103s vs 98s, hardware dependent)

For minimal cloud images that do not install either linux-firmware or modules extra the numbers are:

  • 1.3x less disk space used (548MB vs 742MB)

  • 2.2x less peak RAM usage for initrd boot (27MB vs 62MB)

  • 0.4x increase in download size (207MB vs 146MB)

Hopefully, the compromise of download size, relative to the disk space & initrd savings is a win for the majority of platforms and use cases. For users on extremely expensive and metered connections, the likely best saving is to receive air-gapped updates or skip updates.

This was achieved by precompressing kernel modules & firmware files with the maximum level of Zstd compression at package build time; making actual .deb files uncompressed; assembling the initrd using split cpio archives - uncompressed for the pre-compressed files, whilst compressing only the userspace portions of the initrd; enabling in-kernel module decompression support with matching kmod; fixing bugs in all of the above, and landing all of these things in time for the feature freeze. Whilst leveraging the experience and some of the design choices implementations we have already been shipping on Ubuntu Core. Some of these changes are backported to Jammy, but only enough to support smooth upgrades to Mantic and later. Complete gains are only possible to experience on Mantic and later.

The discovered bugs in kernel module loading code likely affect systems that use LoadPin LSM with kernel space module uncompression as used on ChromeOS systems. Hopefully, Kees Cook or other ChromeOS developers pick up the kernel fixes from the stable trees. Or you know, just use Ubuntu kernels as they do get fixes and features like these first.

The team that designed and delivered these changes is large: Benjamin Drung, Andrea Righi, Juerg Haefliger, Julian Andres Klode, Steve Langasek, Michael Hudson-Doyle, Robert Kratky, Adrien Nader, Tim Gardner, Roxana Nicolescu - and myself Dimitri John Ledkov ensuring the most optimal solution is implemented, everything lands on time, and even implementing portions of the final solution.

Hi, It's me, I am a Staff Engineer at Canonical and we are hiring

Lots of additional technical details and benchmarks on a huge range of diverse hardware and architectures, and bikeshedding all the things below:

For questions and comments please post to Kernel section on Ubuntu Discourse.

11 November 2023

Reproducible Builds: Reproducible Builds in October 2023

Welcome to the October 2023 report from the Reproducible Builds project. In these reports we outline the most important things that we have been up to over the past month. As a quick recap, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries.

Reproducible Builds Summit 2023 Between October 31st and November 2nd, we held our seventh Reproducible Builds Summit in Hamburg, Germany! Our summits are a unique gathering that brings together attendees from diverse projects, united by a shared vision of advancing the Reproducible Builds effort, and this instance was no different. During this enriching event, participants had the opportunity to engage in discussions, establish connections and exchange ideas to drive progress in this vital field. A number of concrete outcomes from the summit will documented in the report for November 2023 and elsewhere. Amazingly the agenda and all notes from all sessions are already online. The Reproducible Builds team would like to thank our event sponsors who include Mullvad VPN, openSUSE, Debian, Software Freedom Conservancy, Allotropia and Aspiration Tech.

Reflections on Reflections on Trusting Trust Russ Cox posted a fascinating article on his blog prompted by the fortieth anniversary of Ken Thompson s award-winning paper, Reflections on Trusting Trust:
[ ] In March 2023, Ken gave the closing keynote [and] during the Q&A session, someone jokingly asked about the Turing award lecture, specifically can you tell us right now whether you have a backdoor into every copy of gcc and Linux still today?
Although Ken reveals (or at least claims!) that he has no such backdoor, he does admit that he has the actual code which Russ requests and subsequently dissects in great but accessible detail.

Ecosystem factors of reproducible builds Rahul Bajaj, Eduardo Fernandes, Bram Adams and Ahmed E. Hassan from the Maintenance, Construction and Intelligence of Software (MCIS) laboratory within the School of Computing, Queen s University in Ontario, Canada have published a paper on the Time to fix, causes and correlation with external ecosystem factors of unreproducible builds. The authors compare various response times within the Debian and Arch Linux distributions including, for example:
Arch Linux packages become reproducible a median of 30 days quicker when compared to Debian packages, while Debian packages remain reproducible for a median of 68 days longer once fixed.
A full PDF of their paper is available online, as are many other interesting papers on MCIS publication page.

NixOS installation image reproducible On the NixOS Discourse instance, Arnout Engelen (raboof) announced that NixOS have created an independent, bit-for-bit identical rebuilding of the nixos-minimal image that is used to install NixOS. In their post, Arnout details what exactly can be reproduced, and even includes some of the history of this endeavour:
You may remember a 2021 announcement that the minimal ISO was 100% reproducible. While back then we successfully tested that all packages that were needed to build the ISO were individually reproducible, actually rebuilding the ISO still introduced differences. This was due to some remaining problems in the hydra cache and the way the ISO was created. By the time we fixed those, regressions had popped up (notably an upstream problem in Python 3.10), and it isn t until this week that we were back to having everything reproducible and being able to validate the complete chain.
Congratulations to NixOS team for reaching this important milestone! Discussion about this announcement can be found underneath the post itself, as well as on Hacker News.

CPython source tarballs now reproducible Seth Larson published a blog post investigating the reproducibility of the CPython source tarballs. Using diffoscope, reprotest and other tools, Seth documents his work that led to a pull request to make these files reproducible which was merged by ukasz Langa.

New arm64 hardware from Codethink Long-time sponsor of the project, Codethink, have generously replaced our old Moonshot-Slides , which they have generously hosted since 2016 with new KVM-based arm64 hardware. Holger Levsen integrated these new nodes to the Reproducible Builds continuous integration framework.

Community updates On our mailing list during October 2023 there were a number of threads, including:
  • Vagrant Cascadian continued a thread about the implementation details of a snapshot archive server required for reproducing previous builds. [ ]
  • Akihiro Suda shared an update on BuildKit, a toolkit for building Docker container images. Akihiro links to a interesting talk they recently gave at DockerCon titled Reproducible builds with BuildKit for software supply-chain security.
  • Alex Zakharov started a thread discussing and proposing fixes for various tools that create ext4 filesystem images. [ ]
Elsewhere, Pol Dellaiera made a number of improvements to our website, including fixing typos and links [ ][ ], adding a NixOS Flake file [ ] and sorting our publications page by date [ ]. Vagrant Cascadian presented Reproducible Builds All The Way Down at the Open Source Firmware Conference.

Distribution work distro-info is a Debian-oriented tool that can provide information about Debian (and Ubuntu) distributions such as their codenames (eg. bookworm) and so on. This month, Benjamin Drung uploaded a new version of distro-info that added support for the SOURCE_DATE_EPOCH environment variable in order to close bug #1034422. In addition, 8 reviews of packages were added, 74 were updated and 56 were removed this month, all adding to our knowledge about identified issues. Bernhard M. Wiedemann published another monthly report about reproducibility within openSUSE.

Software development The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including: In addition, Chris Lamb fixed an issue in diffoscope, where if the equivalent of file -i returns text/plain, fallback to comparing as a text file. This was originally filed as Debian bug #1053668) by Niels Thykier. [ ] This was then uploaded to Debian (and elsewhere) as version 251.

Reproducibility testing framework The Reproducible Builds project operates a comprehensive testing framework (available at in order to check packages and other artifacts for reproducibility. In October, a number of changes were made by Holger Levsen:
  • Debian-related changes:
    • Refine the handling of package blacklisting, such as sending blacklisting notifications to the #debian-reproducible-changes IRC channel. [ ][ ][ ]
    • Install systemd-oomd on all Debian bookworm nodes (re. Debian bug #1052257). [ ]
    • Detect more cases of failures to delete schroots. [ ]
    • Document various bugs in bookworm which are (currently) being manually worked around. [ ]
  • Node-related changes:
    • Integrate the new arm64 machines from Codethink. [ ][ ][ ][ ][ ][ ]
    • Improve various node cleanup routines. [ ][ ][ ][ ]
    • General node maintenance. [ ][ ][ ][ ]
  • Monitoring-related changes:
    • Remove unused Munin monitoring plugins. [ ]
    • Complain less visibly about too many installed kernels. [ ]
  • Misc:
    • Enhance the firewall handling on Jenkins nodes. [ ][ ][ ][ ]
    • Install the fish shell everywhere. [ ]
In addition, Vagrant Cascadian added some packages and configuration for snapshot experiments. [ ]

If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

17 January 2016

Lunar: Reproducible builds: week 38 in Stretch cycle

What happened in the reproducible builds effort between January 10th and January 16th:

Toolchain fixes Benjamin Drung uploaded mozilla-devscripts/0.43 which sorts the file list in preferences files. Original patch by Reiner Herrmann. Lunar submitted an updated patch series to make timestamps in packages created by dpkg deterministic. To ensure that the mtimes in data.tar are reproducible, with the patches, dpkg-deb uses the --clamp-mtime option added in tar/1.28-1 when available. An updated package has been uploaded to the experimental repository. This removed the need for a modified debhelper as all required changes for reproducibility have been merged or are now covered by dpkg.

Packages fixed The following packages have become reproducible due to changes in their build dependencies: angband-doc, bible-kjv, cgoban, gnugo, pachi, wmpuzzle, wmweather, wmwork, xfaces, xnecview, xscavenger, xtrlock, virt-top. The following packages became reproducible after getting fixed: Some uploads fixed some reproducibility issues, but not all of them: Untested changes: Once again, Vagrant Cascadian is providing another armhf build system, allowing to run 6 more armhf builder jobs, right there. (h01ger) Stop requiring a modified debhelper and adapt to the latest dpkg experimental version by providing a predetermined identifier for the .buildinfo filename. (Mattia Rizzolo, h01ger) New X.509 certificates were set up for and using Let's Encrypt!. Thanks to GlobalSign for providing certificates for the last year free of charge. (h01ger)

Package reviews 131 reviews have been removed, 85 added and 32 updated in the previous week. FTBFS issues filled: 29. Thanks to Chris Lamb, Mattia Rizzolo, and Niko Tyni. New issue identified: timestamps_in_manpages_added_by_golang_cobra.

Misc. Most of the minutes from the meetings held in Athens in December 2015 are now available to the public.

16 August 2015

Benjamin Drung: DebConf 15

I am still alive and currently attending DebConf 15. Feel free to grab me for a talk. I am just shy, not antisocial.

17 July 2015

Simon Kainz: DUCK challenge: week 2

Just a litte update on the DUCK challenge: In the last week, the following packages were fixed and uploaded into unstable: Last week we had 10 packages uploaded & fixed, the current week resulted in 15 fixed packages. So there are currently 25 packages fixed by 20 different uploaders. I really hope i can meet you all at DebConf15!! The list of the fixed and updated packages is availabe here. I will try to update this ~daily. If I missed one of your uploads, please drop me a line. A big "Thank You" to you. There is still lots of time till the end of DebConf15 and the end of the DUCK Challenge, so please get involved. And rememeber: debcheckout fails? FIX MORE URLS

14 November 2013

Benjamin Drung: Wanted: Most secure unencrypted email solution

Dear lazy web, Thanks to the global surveillance disclosures, I am searching for a secure email solution. Using end-to-end encryption seems to be the only secure solution to keep the email content private, but it does not protect your email header. End-to-end encryption has the big drawback that the communication partner has to use it, which is rarely the case. I want to communicate as secure as possible even with people that do not use end-to-end encryption. What is the most secure unencrypted email solution? Should I rent a (virtual) server in my country (Germany) and run my own email server on it? Do you know any reliable, inexpensive server host for such use case?

10 November 2013

Gregor Herrmann: RC bugs 2013/45

here's the list of RC bugs I've worked on during the last week.

5 January 2013

Paul Tagliamonte: Updates to dput-ng since version 1.0

Big release notes since 1.0: We ve got a new list feel free to subscribe!
  * Avoid failing on upload if a pre/post upload hook is missing from the
  * Fix "dcut raises FtpUploadException" by correctly initializing the uploader
    classes from dcut (Closes: #696467)
  * Add bash completions for dput-ng (Closes: #695412).
  * Add in a script to set the default profile depending on the building
    distro (Ubuntu support)
  * Fix a bug where meta-class info won't be loaded if the config file has the
    same name.
  * Add an Ubuntu upload target.
  * Added .udeb detection to the check debs hook.
  * Catch the correct exception falling out of bin/dcut
  * Fix the dput manpages to use --uid rather then the old --dm flag.
  * Fix the CLI flag registration by setting required=True
    in cancel and upload.
  * Move make_delayed_upload above the logging call for sanity's sake.
  * Fix "connects to the host even with -s" (Closes: #695347)
Thanks to everone who s contributed!
     7  Bernhard R. Link
     4  Ansgar Burchardt
     3  Luca Falavigna
     2  Michael Gilbert
     2  Salvatore Bonaccorso
     1  Benjamin Drung
     1  Gergely Nagy
     1  Jakub Wilk
     1  Jimmy Kaplowitz
     1  Luke Faraone
     1  Sandro Tosi
This has been your every-once-in-a-while dput-ng update. We re looking for more code contributions (to make sure everyone s happy), doc updates (etc) or ideas.

27 November 2012

Benjamin Drung: Code name for Ubuntu 18.04 LTS

Every Ubuntu release gets an alliterative code name from Mark Shuttleworth. It is a composition of an adjective and an animal. The upcoming Ubuntu 13.04 has the code name Raring Ringtail . Since nearly the beginning, the code names follow the alphabetical order. We will reach the letter Z with Ubuntu 17.04 if no letters are skipped. Will we wrap then and begin with A again? At UDS-R in Copenhagen, Mark Shuttleworth jokingly said between Jono Bacon s introduction and Mark s keynote speech, that vegetables will be used once we run out of letters. He proposed the code name for Ubuntu 18.04 LTS: Brilliant Broccoli!

23 April 2012

Benjamin Drung: Unreliable SSDs

Today my system froze and failed to reboot. I plugged in an Ubuntu live USB stick and booted from it. Then I discovered the problem that my Intel SSD 320 broke. The output of hdparm is attached to the end of the blog post. You can see that the device size is reduced to 8 MB from 120 GB and the serial number is called BAD_CTX 00000159. The firmware of the SSD was up-to-date and the last firmware update should have fixed the 8 MB bug. The Intel SSD 320 is my second SSD. My first SSD was a Super Talent Ultradrive GX 64GB, which died after around fifteen month of heavy use. It left a big bunch of my data corruption behind. SSDs seems to be very unreliable. Both SSDs died, but I cant remember that one of my HDDs died. $ sudo hdparm -I /dev/sda /dev/sda: ATA device, with non-removable media
Model Number: INTEL SSDSA2CW120G3
Serial Number: BAD_CTX 00000159
Firmware Revision: 4PC10362
Transport: Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6
Used: unknown (minor revision code 0x0029)
Supported: 8 7 6 5
Likely used: 8
Logical max current
cylinders 16383 16
heads 16 16
sectors/track 63 63
CHS current addressable sectors: 16128
LBA user addressable sectors: 16384
LBA48 user addressable sectors: 16384
Logical Sector size: 512 bytes
Physical Sector size: 512 bytes
device size with M = 1024*1024: 8 MBytes
device size with M = 1000*1000: 8 MBytes
cache/buffer size = unknown
Nominal Media Rotation Rate: Solid State Device
LBA, IORDY(can be disabled)
Standby timer values: spec'd by Standard, no device specific minimum
R/W multiple sector transfer: Max = 16 Current = 16
DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
Enabled Supported:
Security Mode feature set
* Power Management feature set
* Write cache
* Look-ahead
* Host Protected Area feature set
* WRITE_BUFFER command
* READ_BUFFER command
* NOP cmd
SET_MAX security extension
* 48-bit Address feature set
* Device Configuration Overlay feature set
* Mandatory FLUSH_CACHE
* General Purpose Logging feature set
* 64-bit World wide name
* Gen1 signaling speed (1.5Gb/s)
* Gen2 signaling speed (3.0Gb/s)
* Phy event counters
* Software settings preservation
* SMART Command Transport (SCT) feature set
* SCT LBA Segment Access (AC2)
* SCT Error Recovery Control (AC3)
* SCT Features Control (AC4)
* SCT Data Tables (AC5)
* Data Set Management TRIM supported (limit 8 blocks)
* Deterministic read ZEROs after TRIM
Master password revision code = 65534
not enabled
not locked
not expired: security count
supported: enhanced erase
Logical Unit WWN Device Identifier: 500151795951d4b9
NAA : 5
IEEE OUI : 001517
Unique ID : 95951d4b9
Checksum: correct

3 July 2011

Benjamin Drung: libkibi ready for testing

Yes, the library is finally called libkibi. The second poll ended with a tie between libbyteprefix (48 votes) and libkibi (45 votes). Then I decided to call the library libkibi. libkibi is hosted on Launchpad. A working version can be pulled from lp:libkibi with bzr. Please test the library, reports bugs, and ask questions. Why you should use libkibi instead of g_format_size_for_display (from GLib):

Benjamin Drung: Nautilus with libkibi

In this Ubuntu cycle, I work on getting the units policy implemented. For this I wrote a library called libkibi. Here are some screen shots how nautilus looks like with libkibi. Some changes are highlighted in red. The file properties will show the file size in base10 and base2: PS: I failed to launch nautilus in English. Therefore the screen shots are in German. PS : You can grab the modified nautilus package for Ubuntu 10.10 (maverick) from my experimental PPA (at your own risk!).

Benjamin Drung: libkibi 0.1 released

The first version of libkibi is released. This library is designed for formatting sizes in bytes for display. The user can configure a preferred prefix style. Packages for Debian unstable and Ubuntu 11.04 (maverick) are uploaded. It contains a README for developers and a byteprefix man page for users, which can be read with man 5 byteprefix once installed. Thanks to Stefano Rivera for writing the man page! For a demonstration how this library used by an application can look like, read my previous post.

Benjamin Drung: How to purge Wine completely

I had Wine installed and wanted to get rid of it completely. I removed the Wine Debian package and what belong to it, but the Windows applications still appeared in the GNOME main menu. I removed the .wine directory and all local wine-related desktop files: rm -rf ~/.wine ~/.local/share/applications/wine
rm -f ~/.local/share/applications/wine-* ~/.local/share/applications/mimeinfo.cache
Now there is no sign left that Wine was installed.

Benjamin Drung: Symptoms of a dying graphic card

All started in December last year. I saw a red and a green pixel on my monitor. Moving the window containing the wrong-colors pixels corrected them. The wrong-colored pixels reappear from time to time in increased quantity. Then a second symptom appeared: The screen went black and came back one second later. This was triggered by moving a window and scrolling. I wasn t sure what the reason was. Either it was a bug somewhere in the X stack or some hardware was dying. dmesg showed multiple problems with the radeon driver:
[283808.667454] radeon 0000:01:00.0: ffff88021f815c00 unpin not necessary
[283808.667820] radeon 0000:01:00.0: GPU softreset
[283808.667823] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0xE57024A4
[283808.667825] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0 00330302
[283808.667826] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200000C0
[283808.667832] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0x00007FEE
[283808.682844] radeon 0000:01:00.0: R_008020_GRBM_SOFT_RESET=0 00000001
[283808.698840] radeon 0000:01:00.0: R_008010_GRBM_STATUS=0 00003028
[283808.698843] radeon 0000:01:00.0: R_008014_GRBM_STATUS2=0 00000002
[283808.698845] radeon 0000:01:00.0: R_000E50_SRBM_STATUS=0x200000C0
[283808.699845] radeon 0000:01:00.0: GPU reset succeed
[283808.717570] [drm] Clocks initialized !
[283808.765829] [drm] ring test succeeded in 0 usecs
[283808.765838] [drm] ib test succeeded in 1 usecs
[283808.765840] [drm] Enabling audio support
[283812.521265] radeon 0000:01:00.0: GPU lockup CP stall for more than 1000msec
[283812.521269] [ cut here ]
[283812.521294] WARNING: at /build/buildd/linux-2.6.35/drivers/gpu/drm/radeon/radeon_fence.c:235 radeon_fence_wait+0 365/0x3d0 [radeon]()
[283812.521297] Hardware name:
[283812.521299] GPU lockup (waiting for 0x00AE670A last fence id 0x00AE6705)
[283812.521301] Modules linked in: btrfs zlib_deflate crc32c libcrc32c ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs exportfs reiserfs nls_utf8 udf ip6table_filter ip6_tables binfmt_misc ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp kvm_intel kvm parport_pc ppdev snd_emu10k1_synth snd_emux_synth snd_seq_virmidi snd_seq_midi_emul snd_emu10k1 snd_ac97_codec ac97_bus snd_pcm snd_page_alloc snd_util_mem snd_hwdep snd_seq_midi radeon snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device ttm snd pl2303 drm_kms_helper coretemp usbserial joydev psmouse soundcore drm serio_raw intel_agp i2c_algo_bit lp parport hid_cherry usbhid hid firewire_ohci firewire_core usb_storage crc_itu_t e1000e ahci libahci pata_marvell
[283812.521360] Pid: 2194, comm: compiz Tainted: G W 2.6.35-24-generic #42-Ubuntu
[283812.521362] Call Trace:
[283812.521370] [<ffffffff8106089f>] warn_slowpath_common+0x7f/0xc0
[283812.521374] [<ffffffff81060996>] warn_slowpath_fmt+0 46/0 50
[283812.521390] [<ffffffffa01bd775>] radeon_fence_wait+0 365/0x3d0 [radeon]
[283812.521394] [<ffffffff8107f730>] ? autoremove_wake_function+0 0/0 40
[283812.521410] [<ffffffffa01bdf71>] radeon_sync_obj_wait+0 11/0 20 [radeon]
[283812.521418] [<ffffffffa01751a3>] ttm_bo_wait+0 103/0x1c0 [ttm]
[283812.521435] [<ffffffffa01d4e1a>] radeon_gem_wait_idle_ioctl+0x9a/0 150 [radeon]
[283812.521447] [<ffffffffa010f433>] drm_ioctl+0 463/0 520 [drm]
[283812.521465] [<ffffffffa01d4d80>] ? radeon_gem_wait_idle_ioctl+0 0/0 150 [radeon]
[283812.521470] [<ffffffff81162f0d>] vfs_ioctl+0x3d/0xd0
[283812.521473] [<ffffffff811637e1>] do_vfs_ioctl+0 81/0 340
[283812.521477] [<ffffffff811535f1>] ? vfs_read+0 181/0x1a0
[283812.521480] [<ffffffff81163b21>] sys_ioctl+0 81/0xa0
[283812.521484] [<ffffffff8100a0f2>] system_call_fastpath+0 16/0x1b
[283812.521487] [ end trace 6d5e03bab743abfa ]
[283812.521493] [drm] Disabling audio support
[283812.525575] [drm:radeon_ib_schedule] *ERROR* radeon: couldn t schedule IB(10).
[283812.525579] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB !
[283812.527021] [drm:radeon_ib_schedule] *ERROR* radeon: couldn t schedule IB(11).
[283812.527024] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB !
[283812.527921] [drm:radeon_ib_schedule] *ERROR* radeon: couldn t schedule IB(12).
[283812.527923] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB !
The time between going black reduces every time. The system wasn t usable any more in the end. After testing that the screen was going blank on other systems like a live CD of Ubuntu and a not noteworthy proprietary system, it was clear that some hardware component was dying. My first assumption was verified after replacing it: My graphic card, a Radeon HD 4670, died. This was three weeks ago and around 25 month after I bought the graphics card. So I didn t have to worry if replacing the fan voided the guarantee, because the guarantee lasts only 24 month. Conclusion:
  1. Not every error is a software bug.
  2. The hardware component with the highest failure rate is the graphics card, followed by the motherboard. Four graphics cards died last year (in four different systems owned by four different people, in three different households).
  3. Not every error is a software bug.

31 March 2011

Benjamin Drung: System cleanup

Tonight was system cleanup day. Baobob showed me where are the gigabytes hide. The home directory got rid of huge, old VCS checkouts of various projects. Then it was time to look at the system directories. I cleaned my apt cache sudo apt-get clean and the cache from pbuilder. Then I found something that lead to this blog post: /var/log consumed 3.8 GB. The biggest files were 1.8 GB /var/log/kern.log
1.8 GB /var/log/syslog
4.3 MB /var/log/dpkg.log
1.4 MB /var/log/kern.log.1
Flattr this

30 March 2011

Benjamin Drung: Hardware review I

This month I built two systems with identical hardware component (except for the case). Here s the list of components: Cases often don t meet my high requirements. Many cases are sharp-edged, bad designed (inside and outside), use cheep plastic, and/or vibrate, because the hard drives confer their vibration to the case. The Sugo SG02-F case is not perfect, but I will recommend it. The Silentium T11 case has no shard edges, but I won t recommend it. Too much plastic and optical not appealing. You probably have to replace the boxed CPU heat sink and use a better power supply if you want a silent system. How well do these components work with Ubuntu 10.10 (and probably other recent GNU/Linux distributions)? Perfectly. Everything that I tested worked: Flattr this

Benjamin Drung: First interview

Kristian Ki ling from the Ubuntu User magazine interviewed me at the last Ubucon. You can read the (German) interview in Ubuntu User 02/2011 or on-line. Flattr this

18 January 2011

Benjamin Drung: Poll: How to call the library?

Dear lazy web, I am writing a library that implements the Units Policy of Ubuntu. This library can be used to format sizes (of files, disks, memory, etc.) for displaying them and the other way around. For example, the size 12345 bytes can be formatted to 12.3 kB, 12.1 KiB, or 12.1 KB depending on the configuration. An other function will give you the possibility to convert 12.3 kB, 12.1 KiB, or 12.1 KB back to 12345 bytes. The preferred binary unit can be configured by an text file (per system and per user) and by an environment variable. The library is written in C and doesn t have any dependency. Therefore it can be used by any program on any desktop environment. Binding to other languages like C++, Python, Java are planned. Before creating a project for this library, I need a name for the library. The current prototype is called libdisplayunits, but this name reflect only the half of the project. It does not indicate that the library can be used for inputting sizes. What do you think? What is the best name for the library? Please poll and/or comment below.

<script charset="utf-8" language="javascript" src="" type="text/javascript"></script> <noscript> View This Poll
survey software </noscript>

Benjamin Drung: Poll: libkibi VS libbyteprefix (or: How to call the library? 2)

Dear lazy web, thanks for voting the best name for the library that helps implementing the Units Policy of Ubuntu. The winner with the most votes has been libkibi. There was one suggestion that got my attention: libbyteprefix. The suggestion came too late to have a chance. Therefore I ask you again to vote for the library name, but this time only these two names are open for voting: libkibi and libbyteprefix. libkibi is short and sounds good. On the other hand, libbyteprefix describes exactly what the library is supposed to do. I was asked to use a free (as in freedom) poll-service. So please go to the Selectricity unitspolity vote and select your favorite. Thanks.