Petter Reinholdtsen

First Jessie based Debian Edu released (alpha0)
27th October 2014

I am happy to report that I on behalf of the Debian Edu team just sent out this announcement:

The Debian Edu Team is pleased to announce the release of Debian Edu
Jessie 8.0+edu0~alpha0

Debian Edu is a complete operating system for schools. Through its
various installation profiles you can install servers, workstations
and laptops which will work together on the school network. With
Debian Edu, the teachers themselves or their technical support can
roll out a complete multi-user multi-machine study environment within
hours or a few days. Debian Edu comes with hundreds of applications
pre-installed, but you can always add more packages from Debian.

For those who want to give Debian Edu Jessie a try, download and
installation instructions are available, including detailed
instructions in the manual[1] explaining the first steps, such as
setting up a network or adding users. Please note that the password
for the user your prompted for during installation must have a length
of at least 5 characters!

 [1] <URL: >

Would you like to give your school's computer a longer life? Are you
tired of sneaker administration, running from computer to computer
reinstalling the operating system? Would you like to administrate all
the computers in your school using only a couple of hours every week?
Check out Debian Edu Jessie!

Skolelinux is used by at least two hundred schools all over the world,
mostly in Germany and Norway.

About Debian Edu and Skolelinux

Debian Edu, also known as Skolelinux[2], is a Linux distribution based
on Debian providing an out-of-the box environment of a completely
configured school network. Immediately after installation a school
server running all services needed for a school network is set up just
waiting for users and machines being added via GOsa², a comfortable
Web-UI. A netbooting environment is prepared using PXE, so after
initial installation of the main server from CD or USB stick all other
machines can be installed via the network.  The provided school server
provides LDAP database and Kerberos authentication service,
centralized home directories, DHCP server, web proxy and many other
services.  The desktop contains more than 60 educational software
packages[3] and more are available from the Debian archive, and
schools can choose between KDE, Gnome, LXDE, Xfce and MATE desktop

 [2] <URL: >
 [3] <URL: >

Full release notes and manual

Below the download URLs there is a list of some of the new features
and bugfixes of Debian Edu 8.0+edu0~alpha0 Codename Jessie. The full
list is part of the manual. (See the feature list in the manual[4] for
the English version.) For some languages manual translations are
available, see the manual translation overview[5].

 [4] <URL: >
 [5] <URL: >

Where to get it

To download the multiarch netinstall CD release (624 MiB) you can use

 * rsync -avzP .

The SHA1SUM of this image is: 361188818e036ce67280a572f757de82ebfeb095

New features for Debian Edu 8.0+edu0~alpha0 Codename Jessie released 2014-10-27

Installation changes

 * PXE installation now installs firmware automatically for the hardware present.

Software updates

Everything which is new in Debian Jessie 8.0, eg:

 * Linux kernel 3.16.x
 * Desktop environments KDE "Plasma" 4.11.12, GNOME 3.14, Xfce 4.10,
   LXDE 0.5.6 and MATE 1.8 (KDE "Plasma" is installed by default; to
   choose one of the others see manual.)
 * the browsers Iceweasel 31 ESR and Chromium 38 
 * !LibreOffice 4.3.3
 * GOsa 2.7.4
 * LTSP 5.5.4
 * CUPS print system 1.7.5
 * new boot framework: systemd
 * Educational toolbox GCompris 14.07 
 * Music creator Rosegarden 14.02
 * Image editor Gimp 2.8.14
 * Virtual stargazer Stellarium 0.13.0
 * golearn 0.9
 * tuxpaint 0.9.22
 * New version of debian-installer from Debian Jessie.
 * Debian Jessie includes about 42000 packages available for
 * More information about Debian Jessie 8.0 is provided in the release
   notes[6] and the installation manual[7].

 [6] <URL: >
 [7] <URL: >

Fixed bugs

 * Inserting incorrect DNS information in Gosa will no longer break
   DNS completely, but instead stop DNS updates until the incorrect
   information is corrected (Debian bug #710362)
 * and many others.

Documentation and translation updates

 * The Debian Edu Jessie Manual is fully translated to German, French,
   Italian, Danish and Dutch. Partly translated versions exist for
   Norwegian Bokmal and Spanish.

Other changes

 * Due to new Squid settings, powering off or rebooting the main
   server takes more time.
 * To manage printers localhost:631 has to be used, currently www:631
   doesn't work.

Regressions / known problems

 * Installing LTSP chroot fails with a bug related to eatmydata about
   exim4-config failing to run its postinst (see Debian bug #765694
   and Debian bug #762103).
 * Munin collection is not properly configured on clients (Debian bug
   #764594).  The fix is available in a newer version of munin-node.
 * PXE setup for Main Server and Thin Client Server setup does not
   work when installing on a machine without direct Internet access.
   Will be fixed when Debian bug #766960 is fixed in Jessie.

See the status page[8] for the complete list.

 [8] <URL: >

How to report bugs

<URL: >

About Debian

The Debian Project was founded in 1993 by Ian Murdock to be a truly
free community project. Since then the project has grown to be one of
the largest and most influential open source projects. Thousands of
volunteers from all over the world work together to create and
maintain Debian software. Available in 70 languages, and supporting a
huge range of computer types, Debian calls itself the universal
operating system.

Contact Information
For further information, please visit the Debian web pages[9] or send
mail to

 [9] <URL: >
Tags: debian edu, english.
I spent last weekend recording MakerCon Nordic
23rd October 2014

I spent last weekend at Makercon Nordic, a great conference and workshop for makers in Norway and the surrounding countries. I had volunteered on behalf of the Norwegian Unix Users Group (NUUG) to video record the talks, and we had a great and exhausting time recording the entire day, two days in a row. There were only two of us, Hans-Petter and me, and we used the regular video equipment for NUUG, with a dvswitch, a camera and a VGA to DV convert box, and mixed video and slides live.

Hans-Petter did the post-processing, consisting of uploading the around 180 GiB of raw video to Youtube, and the result is now becoming public on the MakerConNordic account. The videos have the license NUUG always use on our recordings, which is Creative Commons Navngivelse-Del på samme vilkår 3.0 Norge. Many great talks available. Check it out! :)

Tags: english, nuug, video.
listadmin, the quick way to moderate mailman lists - nice free software
22nd October 2014

If you ever had to moderate a mailman list, like the ones on, you know the web interface is fairly slow to operate. First you visit one web page, enter the moderation password and get a new page shown with a list of all the messages to moderate and various options for each email address. This take a while for every list you moderate, and you need to do it regularly to do a good job as a list moderator. But there is a quick alternative, the listadmin program. It allow you to check lists for new messages to moderate in a fraction of a second. Here is a test run on two lists I recently took over:

% time listadmin xiph
fetching data for ... nothing in queue
fetching data for ... nothing in queue

real    0m1.709s
user    0m0.232s
sys     0m0.012s

In 1.7 seconds I had checked two mailing lists and confirmed that there are no message in the moderation queue. Every morning I currently moderate 68 mailman lists, and it normally take around two minutes. When I took over the two pkg-xiph lists above a few days ago, there were 400 emails waiting in the moderator queue. It took me less than 15 minutes to process them all using the listadmin program.

If you install the listadmin package from Debian and create a file ~/.listadmin.ini with content like this, the moderation task is a breeze:

spamlevel 23
default discard
discard_if_reason "Posting restricted to members only. Remove us from your mail list."

password secret
adminurl https://{domain}/mailman/admindb/{list}

password hidden

There are other options to set as well. Check the manual page to learn the details.

If you are forced to moderate lists on a mailman installation where the SSL certificate is self signed or not properly signed by a generally accepted signing authority, you can set a environment variable when calling listadmin to disable SSL verification:


If you want to moderate a subset of the lists you take care of, you can provide an argument to the listadmin script like I do in the initial screen dump (the xiph argument). Using an argument, only lists matching the argument string will be processed. This make it quick to accept messages if you notice the moderation request in your email.

Without the listadmin program, I would never be the moderator of 68 mailing lists, as I simply do not have time to spend on that if the process was any slower. The listadmin program have saved me hours of time I could spend elsewhere over the years. It truly is nice free software.

As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

Update 2014-10-27: Added missing 'username' statement in configuration example. Also, I've been told that the PERL_LWP_SSL_VERIFY_HOSTNAME=0 setting do not work for everyone. Not sure why.

Tags: debian, english.
Debian Jessie, PXE and automatic firmware installation
17th October 2014

When PXE installing laptops with Debian, I often run into the problem that the WiFi card require some firmware to work properly. And it has been a pain to fix this using preseeding in Debian. Normally something more is needed. But thanks to my isenkram package and its recent tasksel extension, it has now become easy to do this using simple preseeding.

The isenkram-cli package provide tasksel tasks which will install firmware for the hardware found in the machine (actually, requested by the kernel modules for the hardware). (It can also install user space programs supporting the hardware detected, but that is not the focus of this story.)

To get this working in the default installation, two preeseding values are needed. First, the isenkram-cli package must be installed into the target chroot (aka the hard drive) before tasksel is executed in the pkgsel step of the debian-installer system. This is done by preseeding the base-installer/includes debconf value to include the isenkram-cli package. The package name is next passed to debootstrap for installation. With the isenkram-cli package in place, tasksel will automatically use the isenkram tasks to detect hardware specific packages for the machine being installed and install them, because isenkram-cli contain tasksel tasks.

Second, one need to enable the non-free APT repository, because most firmware unfortunately is non-free. This is done by preseeding the apt-mirror-setup step. This is unfortunate, but for a lot of hardware it is the only option in Debian.

The end result is two lines needed in your preseeding file to get firmware installed automatically by the installer:

base-installer base-installer/includes string isenkram-cli
apt-mirror-setup apt-setup/non-free boolean true

The current version of isenkram-cli in testing/jessie will install both firmware and user space packages when using this method. It also do not work well, so use version 0.15 or later. Installing both firmware and user space packages might give you a bit more than you want, so I decided to split the tasksel task in two, one for firmware and one for user space programs. The firmware task is enabled by default, while the one for user space programs is not. This split is implemented in the package currently in unstable.

If you decide to give this a go, please let me know (via email) how this recipe work for you. :)

So, I bet you are wondering, how can this work. First and foremost, it work because tasksel is modular, and driven by whatever files it find in /usr/lib/tasksel/ and /usr/share/tasksel/. So the isenkram-cli package place two files for tasksel to find. First there is the task description file (/usr/share/tasksel/descs/isenkram.desc):

Task: isenkram-packages
Section: hardware
Description: Hardware specific packages (autodetected by isenkram)
 Based on the detected hardware various hardware specific packages are
Test-new-install: show show
Relevance: 8
Packages: for-current-hardware

Task: isenkram-firmware
Section: hardware
Description: Hardware specific firmware packages (autodetected by isenkram)
 Based on the detected hardware various hardware specific firmware
 packages are proposed.
Test-new-install: mark show
Relevance: 8
Packages: for-current-hardware-firmware

The key parts are Test-new-install which indicate how the task should be handled and the Packages line referencing to a script in /usr/lib/tasksel/packages/. The scripts use other scripts to get a list of packages to install. The for-current-hardware-firmware script look like this to list relevant firmware for the machine:

export PATH
isenkram-autoinstall-firmware -l

With those two pieces in place, the firmware is installed by tasksel during the normal d-i run. :)

If you want to test what tasksel will install when isenkram-cli is installed, run DEBIAN_PRIORITY=critical tasksel --test --new-install to get the list of packages that tasksel would install.

Debian Edu will be pilots in testing this feature, as isenkram is used there now to install firmware, replacing the earlier scripts.

Tags: debian, english, isenkram, sysadmin.
Ubuntu used to show the bread prizes at ICA Storo
4th October 2014

Today I came across an unexpected Ubuntu boot screen. Above the bread shelf on the ICA shop at Storo in Oslo, the grub menu of Ubuntu with Linux kernel 3.2.0-23 (ie probably version 12.04 LTS) was stuck on a screen normally showing the bread types and prizes:

If it had booted as it was supposed to, I would never had known about this hidden Linux installation. It is interesting what errors can reveal.

Tags: debian, english.
New lsdvd release version 0.17 is ready
4th October 2014

The lsdvd project got a new set of developers a few weeks ago, after the original developer decided to step down and pass the project to fresh blood. This project is now maintained by Petter Reinholdtsen and Steve Dibb.

I just wrapped up a new lsdvd release, available in git or from the download page. This is the changelog dated 2014-10-03 for version 0.17.

This change bring together patches for lsdvd in use in various Linux and Unix distributions, as well as patches submitted to the project the last nine years. Please check it out. :)

Tags: debian, english, lsdvd, multimedia.
How to test Debian Edu Jessie despite some fatal problems with the installer
26th September 2014

The Debian Edu / Skolelinux project provide a Linux solution for schools, including a powerful desktop with education software, a central server providing web pages, user database, user home directories, central login and PXE boot of both clients without disk and the installation to install Debian Edu on machines with disk (and a few other services perhaps to small to mention here). We in the Debian Edu team are currently working on the Jessie based version, trying to get everything in shape before the freeze, to avoid having to maintain our own package repository in the future. The current status can be seen on the Debian wiki, and there is still heaps of work left. Some fatal problems block testing, breaking the installer, but it is possible to work around these to get anyway. Here is a recipe on how to get the installation limping along.

First, download the test ISO via ftp, http or rsync (use The ISO build was broken on Tuesday, so we do not get a new ISO every 12 hours or so, but thankfully the ISO we already got we are able to install with some tweaking.

When you get to the Debian Edu profile question, go to tty2 (use Alt-Ctrl-F2), run

nano /usr/bin/edu-eatmydata-install

and add 'exit 0' as the second line, disabling the eatmydata optimization. Return to the installation, select the profile you want and continue. Without this change, exim4-config will fail to install due to a known bug in eatmydata.

When you get the grub question at the end, answer /dev/sda (or if this do not work, figure out what your correct value would be. All my test machines need /dev/sda, so I have no advice if it do not fit your need.

If you installed a profile including a graphical desktop, log in as root after the initial boot from hard drive, and install the education-desktop-XXX metapackage. XXX can be kde, gnome, lxde, xfce or mate. If you want several desktop options, install more than one metapackage. Once this is done, reboot and you should have a working graphical login screen. This workaround should no longer be needed once the education-tasks package version 1.801 enter testing in two days.

I believe the ISO build will start working on two days when the new tasksel package enter testing and Steve McIntyre get a chance to update the debian-cd git repository. The eatmydata, grub and desktop issues are already fixed in unstable and testing, and should show up on the ISO as soon as the ISO build start working again. Well the eatmydata optimization is really just disabled. The proper fix require an upload by the eatmydata maintainer applying the patch provided in bug #702711. The rest have proper fixes in unstable.

I hope this get you going with the installation testing, as we are quickly running out of time trying to get our Jessie based installation ready before the distribution freeze in a month.

Tags: debian, debian edu, english.
Suddenly I am the new upstream of the lsdvd command line tool
25th September 2014

I use the lsdvd tool to handle my fairly large DVD collection. It is a nice command line tool to get details about a DVD, like title, tracks, track length, etc, in XML, Perl or human readable format. But lsdvd have not seen any new development since 2006 and had a few irritating bugs affecting its use with some DVDs. Upstream seemed to be dead, and in January I sent a small probe asking for a version control repository for the project, without any reply. But I use it regularly and would like to get an updated version into Debian. So two weeks ago I tried harder to get in touch with the project admin, and after getting a reply from him explaining that he was no longer interested in the project, I asked if I could take over. And yesterday, I became project admin.

I've been in touch with a Gentoo developer and the Debian maintainer interested in joining forces to maintain the upstream project, and I hope we can get a new release out fairly quickly, collecting the patches spread around on the internet into on place. I've added the relevant Debian patches to the freshly created git repository, and expect the Gentoo patches to make it too. If you got a DVD collection and care about command line tools, check out the git source and join the project mailing list. :)

Tags: debian, english, lsdvd, multimedia.
Hva henger under skibrua over E16 på Sollihøgda?
21st September 2014

Rundt omkring i Oslo og Østlandsområdet henger det bokser over veiene som jeg har lurt på hva gjør. De har ut fra plassering og vinkling sett ut som bokser som sniffer ut et eller annet fra forbipasserende trafikk, men det har vært uklart for meg hva det er de leser av. Her om dagen tok jeg bilde av en slik boks som henger under ei skibru på Sollihøgda:

Boksen er tydelig merket «Kapsch >>>», logoen til det sveitsiske selskapet Kapsch som blant annet lager sensorsystemer for veitrafikk. Men de lager mye forskjellig, og jeg kjente ikke igjen boksen på utseendet etter en kjapp titt på produktlista til selskapet.

I og med at boksen henger over veien E16, en riksvei vedlikeholdt av Statens Vegvesen, så antok jeg at det burde være mulig å bruke REST-API-et som gir tilgang til vegvesenets database over veier, skilter og annet veirelatert til å finne ut hva i alle dager dette kunne være. De har både en datakatalog og et søk, der en kan søke etter ulike typer oppføringer innen for et gitt geografisk område. Jeg laget et enkelt shell-script for å hente ut antall av en gitt type innenfor området skibrua dekker, og listet opp navnet på typene som ble funnet. Orket ikke slå opp hvordan URL-koding av aktuelle strenger kunne gjøres mer generisk, og brukte en stygg sed-linje i stedet.

urlmap() {
    sed \
    -e 's/  / /g'   -e 's/{/%7B/g'  \
    -e 's/}/%7D/g'  -e 's/\[/%5B/g' \
    -e 's/\]/%5D/g' -e 's/ /%20/g'  \
    -e 's/,/%2C/g'  -e 's/\"/%22/g' \
    -e 's/:/%3A/g'

lookup() {
    curl -s -H 'Accept: application/vnd.vegvesen.nvdb-v1+xml' \
       "$url" | xmllint --format -

for id in $(seq 1 874) ; do
  lokasjon: {
    bbox: \"10.34425,59.96386,10.34458,59.96409\",
    srid: \"WGS84\"
   objektTyper: [{
     id: $id, antall: 10

    query=/sok?kriterie=$(echo $search | urlmap)
    if lookup "$query" |
    grep -q '<totaltAntallReturnert>0<'
    echo $id
    lookup "/datakatalog/objekttyper/$id" |grep '^  <navn>'

exit 0
Aktuelt ID-område 1-874 var riktig i datakatalogen da jeg laget scriptet. Det vil endre seg over tid. Skriptet listet så opp aktuelle typer i og rundt skibrua:
  <navn>Grøft, åpen</navn>
  <navn>Vegoppmerking, langsgående</navn>
  <navn>Ulykkesinvolvert enhet</navn>
  <navn>Ulykkesinvolvert person</navn>
  <navn>Støy-luft, Strekningsdata</navn>
  <navn>Værrelatert strekning</navn>
  <navn>Vegdekke, flatelapping</navn>
  <navn>Kurvatur, horisontalelement</navn>
  <navn>Kurvatur, vertikalelement</navn>
  <navn>Kurvatur, vertikalpunkt</navn>
  <navn>Statistikk, trafikkmengde</navn>
  <navn>Statistikk, vegbredde</navn>
  <navn>ATK, influensstrekning</navn>
  <navn>Funksjonell vegklasse</navn>
  <navn>Kurvatur, stigning</navn>
  <navn>Vegbredde, beregnet</navn>

Av disse ser ID 775 og 862 mest relevant ut. ID 775 antar jeg refererer til fotoboksen som står like ved brua, mens «Reisetidsregistreringspunkt» kanskje kan være boksen som henger der. Hvordan finner jeg så ut hva dette kan være for noe. En titt på datakatalogsiden for ID 862/Reisetidsregistreringspunkt viser at det er finnes 53 slike målere i Norge, og hvor de er plassert, men gir ellers få detaljer. Det er plassert 40 på østlandet og 13 i Trondheimsregionen. Men siden nevner «AutoPASS», og hvis en slår opp oppføringen på Sollihøgda nevner den «Ciber AS» som ID for eksternt system. (Kan det være snakk om Ciber Norge AS, et selskap eid av Ciber Europe Bv?) Et nettsøk på «Ciber AS autopass» fører meg til en artikkel fra NRK Trøndelag i 2013 med tittel «Sjekk dette hvis du vil unngå kø». Artikkelen henviser til vegvesenets nettside som har en kartside for Østlandet som viser at det måles mellom Sandvika og Sollihøgda. Det kan dermed se ut til at jeg har funnet ut hva boksene gjør.

Hvis det stemmer, så er dette bokser som leser av AutoPASS-ID-en til alle passerende biler med AutoPASS-brikke, og dermed gjør det mulig for de som kontrollerer boksene å holde rede på hvor en gitt bil er når den passerte et slikt målepunkt. NRK-artikkelen forteller at denne informasjonen i dag kun brukes til å koble to AutoPASS-brikkepasseringer passeringer sammen for å beregne reisetiden, og at bruken er godkjent av Datatilsynet. Det er desverre ikke mulig for en sjåfør som passerer under en slik boks å kontrollere at AutoPASS-ID-en kun brukes til dette i dag og i fremtiden.

I tillegg til denne type AutoPASS-sniffere vet jeg at det også finnes mange automatiske stasjoner som tar betalt pr. passering (aka bomstasjoner), og der lagres informasjon om tid, sted og bilnummer i 10 år. Finnes det andre slike sniffere plassert ut på veiene?

Personlig har jeg valgt å ikke bruke AutoPASS-brikke, for å gjøre det vanskeligere og mer kostbart for de som vil invadere privatsfæren og holde rede på hvor bilen min beveger seg til enhver tid. Jeg håper flere vil gjøre det samme, selv om det gir litt høyere private utgifter (dyrere bompassering). Vern om privatsfæren koster i disse dager.

Takk til Jan Kristian Jensen i Statens Vegvesen for tips om dokumentasjon på vegvesenets REST-API.

Tags: kart, norsk, personvern, rfid, surveillance.
Speeding up the Debian installer using eatmydata and dpkg-divert
16th September 2014

The Debian installer could be a lot quicker. When we install more than 2000 packages in Skolelinux / Debian Edu using tasksel in the installer, unpacking the binary packages take forever. A part of the slow I/O issue was discussed in bug #613428 about too much file system sync-ing done by dpkg, which is the package responsible for unpacking the binary packages. Other parts (like code executed by postinst scripts) might also sync to disk during installation. All this sync-ing to disk do not really make sense to me. If the machine crash half-way through, I start over, I do not try to salvage the half installed system. So the failure sync-ing is supposed to protect against, hardware or system crash, is not really relevant while the installer is running.

A few days ago, I thought of a way to get rid of all the file system sync()-ing in a fairly non-intrusive way, without the need to change the code in several packages. The idea is not new, but I have not heard anyone propose the approach using dpkg-divert before. It depend on the small and clever package eatmydata, which uses LD_PRELOAD to replace the system functions for syncing data to disk with functions doing nothing, thus allowing programs to live dangerous while speeding up disk I/O significantly. Instead of modifying the implementation of dpkg, apt and tasksel (which are the packages responsible for selecting, fetching and installing packages), it occurred to me that we could just divert the programs away, replace them with a simple shell wrapper calling "eatmydata $program $@", to get the same effect. Two days ago I decided to test the idea, and wrapped up a simple implementation for the Debian Edu udeb.

The effect was stunning. In my first test it reduced the running time of the pkgsel step (installing tasks) from 64 to less than 44 minutes (20 minutes shaved off the installation) on an old Dell Latitude D505 machine. I am not quite sure what the optimised time would have been, as I messed up the testing a bit, causing the debconf priority to get low enough for two questions to pop up during installation. As soon as I saw the questions I moved the installation along, but do not know how long the question were holding up the installation. I did some more measurements using Debian Edu Jessie, and got these results. The time measured is the time stamp in /var/log/syslog between the "pkgsel: starting tasksel" and the "pkgsel: finishing up" lines, if you want to do the same measurement yourself. In Debian Edu, the tasksel dialog do not show up, and the timing thus do not depend on how quickly the user handle the tasksel dialog.

Machine/setup Original tasksel Optimised tasksel Reduction
Latitude D505 Main+LTSP LXDE 64 min (07:46-08:50) <44 min (11:27-12:11) >20 min 18%
Latitude D505 Roaming LXDE 57 min (08:48-09:45) 34 min (07:43-08:17) 23 min 40%
Latitude D505 Minimal 22 min (10:37-10:59) 11 min (11:16-11:27) 11 min 50%
Thinkpad X200 Minimal 6 min (08:19-08:25) 4 min (08:04-08:08) 2 min 33%
Thinkpad X200 Roaming KDE 19 min (09:21-09:40) 15 min (10:25-10:40) 4 min 21%

The test is done using a netinst ISO on a USB stick, so some of the time is spent downloading packages. The connection to the Internet was 100Mbit/s during testing, so downloading should not be a significant factor in the measurement. Download typically took a few seconds to a few minutes, depending on the amount of packages being installed.

The speedup is implemented by using two hooks in Debian Installer, the pre-pkgsel.d hook to set up the diverts, and the finish-install.d hook to remove the divert at the end of the installation. I picked the pre-pkgsel.d hook instead of the post-base-installer.d hook because I test using an ISO without the eatmydata package included, and the post-base-installer.d hook in Debian Edu can only operate on packages included in the ISO. The negative effect of this is that I am unable to activate this optimization for the kernel installation step in d-i. If the code is moved to the post-base-installer.d hook, the speedup would be larger for the entire installation.

I've implemented this in the debian-edu-install git repository, and plan to provide the optimization as part of the Debian Edu installation. If you want to test this yourself, you can create two files in the installer (or in an udeb). One shell script need do go into /usr/lib/pre-pkgsel.d/, with content like this:

set -e
. /usr/share/debconf/confmodule
info() {
    logger -t my-pkgsel "info: $*"
error() {
    logger -t my-pkgsel "error: $*"
override_install() {
    apt-install eatmydata || true
    if [ -x /target/usr/bin/eatmydata ] ; then
        for bin in dpkg apt-get aptitude tasksel ; do
            # Test that the file exist and have not been diverted already.
            if [ -f /target$file ] ; then
                info "diverting $file using eatmydata"
                printf "#!/bin/sh\neatmydata $bin.distrib \"\$@\"\n" \
                    > /target$
                chmod 755 /target$
                in-target dpkg-divert --package debian-edu-config \
                    --rename --quiet --add $file
                ln -sf ./$ /target$file
                error "unable to divert $file, as it is missing."
        error "unable to find /usr/bin/eatmydata after installing the eatmydata pacage"


To clean up, another shell script should go into /usr/lib/finish-install.d/ with code like this:

#! /bin/sh -e
. /usr/share/debconf/confmodule
error() {
    logger -t my-finish-install "error: $@"
remove_install_override() {
    for bin in dpkg apt-get aptitude tasksel ; do
        if [ -x /target$ ] ; then
            rm /target$file
            in-target dpkg-divert --package debian-edu-config \
                --rename --quiet --remove $file
            rm /target$
            error "Missing divert for $file."
    sync # Flush file buffers before continuing


In Debian Edu, I placed both code fragments in a separate script edu-eatmydata-install and call it from the pre-pkgsel.d and finish-install.d scripts.

By now you might ask if this change should get into the normal Debian installer too? I suspect it should, but am not sure the current debian-installer coordinators find it useful enough. It also depend on the side effects of the change. I'm not aware of any, but I guess we will see if the change is safe after some more testing. Perhaps there is some package in Debian depending on sync() and fsync() having effect? Perhaps it should go into its own udeb, to allow those of us wanting to enable it to do so without affecting everyone.

Update 2014-09-24: Since a few days ago, enabling this optimization will break installation of all programs using gnutls because of bug #702711. An updated eatmydata package in Debian will solve it.

Update 2014-10-17: The bug mentioned above is fixed in testing and the optimization work again. And I have discovered that the dpkg-divert trick is not really needed and implemented a slightly simpler approach as part of the debian-edu-install package. See tools/edu-eatmydata-install in the source package.

Tags: debian, debian edu, english.

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