<item>
- <title>Second beta version of Debian Edu / Skolelinux based on Squeeze</title>
- <link>http://people.skolelinux.org/pere/blog/Second_beta_version_of_Debian_Edu___Skolelinux_based_on_Squeeze.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Second_beta_version_of_Debian_Edu___Skolelinux_based_on_Squeeze.html</guid>
- <pubDate>Tue, 7 Feb 2012 22:50:00 +0100</pubDate>
- <description><p>I am happy to announce that today we managed to wrap up and publish
-the second beta version of
-<a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a>. If
-you want to test a LDAP backed Kerberos server with out of the box PXE
-configuration for running diskless machines and installing new
-machines, check it out. If you need a software solution for your
-school, check it out too. The full announcement is
-<a href="http://lists.debian.org/debian-edu-announce/2012/01/msg00000.html">available</a>
+ <title>Third beta version of Debian Edu / Skolelinux based on Squeeze</title>
+ <link>http://people.skolelinux.org/pere/blog/Third_beta_version_of_Debian_Edu___Skolelinux_based_on_Squeeze.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Third_beta_version_of_Debian_Edu___Skolelinux_based_on_Squeeze.html</guid>
+ <pubDate>Sat, 4 Feb 2012 13:25:00 +0100</pubDate>
+ <description><p>I am happy to announce that finally we managed today to wrap up and
+publish the third beta version of
+<a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a> based
+on Squeeze. If you want to test a LDAP backed Kerberos server with
+out of the box PXE configuration for running diskless machines and
+installing new machines, check it out. If you need a software
+solution for your school, check it out too. The full announcement is
+<a href="http://lists.debian.org/debian-edu-announce/2012/02/msg00000.html">available</a>
on the project announcement list.</p>
+
+<p>I am very happy to report these changes and improvements since
+beta2 (there are more, see announcement for full list):</p>
+
+<ul>
+
+<li>It is now possible to change the pre-configured IP subnet from
+ 10.0.0.0/8 to something else by using the subnet-change tool after
+ the installation.</li>
+
+<li>Too full partitions are now automatically extended on the Main
+ Server, based on the rules specified in /etc/fsautoresizetab.</li>
+
+<li>The CUPS queues are now automatically flushed every night, and all
+ disabled queues are restarted every hour. This should cut down on
+ the amount of manual administration needed for printers.</li>
+
+<li>The set of initial users have been changed. Now a personal user
+ for the local system administrator is created during installation
+ instead of the previously created localadmin and super-admin users,
+ and this user is granted administrative privileges using group
+ membership. This reduces the number of passwords one need to keep
+ up to date on the system.</li>
+
+</ul>
+
+<p>The new main server seem to work so well that I am testing it as my
+private DNS/LDAP/Kerberos/PXE/LTSP server at home. I will use it look
+for issues we could fix to polish Debian Edu even further before the
+final Squeeze release is published.</p>
+
+<p>Next weekend the project organise a
+<a href="http://lists.debian.org/debian-edu-announce/2012/01/msg00001.html">developer
+gathering</a> in Oslo. We will continue the work on the Squeeze
+version, and start initial planning for the Wheezy version. Perhaps I
+will see you there?</p>
+</description>
+ </item>
+
+ <item>
+ <title>Saving power with Debian Edu / Skolelinux using shutdown-at-night</title>
+ <link>http://people.skolelinux.org/pere/blog/Saving_power_with_Debian_Edu___Skolelinux_using_shutdown_at_night.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Saving_power_with_Debian_Edu___Skolelinux_using_shutdown_at_night.html</guid>
+ <pubDate>Sun, 5 Feb 2012 09:45:00 +0100</pubDate>
+ <description><p>Since the Lenny version of
+<a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a>, a
+feature to save power have been included. It is as simple as it is
+practical: Shut down unused clients at night, and turn them on again
+in the morning. This is done using the
+<a href="http://packages.qa.debian.org/s/shutdown-at-night.html">shutdown-at-night</a> Debian package.</p>
+
+<p>To enable this feature on a client, the machine need to be added to
+the netgroup shutdown-at-night-hosts. For Debian Edu, this is done in
+LDAP, and once this is in place, the machine in question will check
+every hour from 16:00 until 06:00 to see if the machine is unused, and
+shut it down if it is. If the hardware in question is supported by
+the
+<a href="http://packages.qa.debian.org/n/nvram-wakeup.html">nvram-wakeup</a>
+package, the BIOS is told to turn the machine back on around 07:00 +-
+10 minutes. If this isn't working, one can configure wake-on-lan to
+try to turn on the client. The wake-on-lan option is only documented
+and not enabled by default in Debian Edu.</p>
+
+<p>It is important to not turn all machines on at once, as this can
+blow a fuse if several computers are connected to the same fuse like
+the common setup for a classroom. The nvram-wakeup method only work
+for machines with a functioning hardware/BIOS clock. I've seen old
+machines where the BIOS battery were dead and the hardware clock were
+starting from 0 (or was it 1990?) every boot. If you have one of
+those, you have to turn on the computer manually.</p>
+
+<p>The shutdown-at-night package is completely self contained, and can
+also be used outside the Debian Edu environment. For those without a
+central LDAP server with netgroups, one can instead touch the file
+<tt>/etc/shutdown-at-night/shutdown-at-night</tt> to enable it.
+Perhaps you too can use it to save some power?</p>
+</description>
+ </item>
+
+ <item>
+ <title>Skolelinux-intervju: Axel Bojer</title>
+ <link>http://people.skolelinux.org/pere/blog/Skolelinux_intervju__Axel_Bojer.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Skolelinux_intervju__Axel_Bojer.html</guid>
+ <pubDate>Tue, 7 Feb 2012 14:50:00 +0100</pubDate>
+ <description><p>I serien med intervjuer av folk i
+<a href="http://www.skolelinux.org/">Skolelinux</a>-miljøet har jeg
+fått en av oversetterne som har vært med siden starten i tale.</p>
+
+<p><strong>Hvem er du, og hva driver du med til daglig?</strong></p>
+
+<p>Jeg heter Axel Bojer og er datalærer, tysklærer, oversetter med
+mere.</p>
+
+<p><strong>Hvordan kom du i kontakt med Skolelinux-prosjektet?</strong></p>
+
+<p>Tror jeg så en annonsering på nettet i slutten av 2001 og ville
+være med som oversetter. Jeg kom med på en utviklersamling og
+prosjektet var da helt i starten. Det var spennende å være med mens
+prosjektet vokste til og utviklet seg.</p>
+
+<p>Jeg har «alltid» vært språkinteressert og hadde nettopp startet med
+Linux og tror jeg tenkte det passet å bidra. Var også glad for å få
+en Debian-distribusjon, og ville gjerne bruke den selv. Til å begynne
+med brukte jeg først Mandrake og så Debian. Og siden jeg oppdaget at
+det ikke var noen mulighet for å bruke den som enkeltstående i lang
+tid, så gikk jeg etterhvert over til Kubuntu</p>
+
+<p><strong>Hva er fordelene med Skolelinux slik du ser det?</strong></p>
+
+<p>Løsningen er forholdsvis lett å sette opp, gratis, fri programvare
+og gjør det mulig å gjenbruke eldre maskiner. Det fine med Debian er
+at det er stabilt og har en veldig stor mengde programmer. Jeg liker
+også apt. :-) Jeg liker også friheten ved Linux og muligheten til å
+delta og forme sin egen datahverdag.</p>
+
+<p><strong>Hva er ulempene med Skolelinux slik du ser det?</strong></p>
+
+<p>Skolelinux er for lite kjent og for sent ute med å gi ut nye
+versjoner.</p>
+
+<p>Da jeg selv i hovedsak bruker Kubuntu, så kan jeg egentlig ikke
+svare så detaljert rundt ulempene med Skolelinux. Hovedårsaken til at
+jeg bruker Kubuntu er nok at da vi begynte med det mener jeg det ikke
+var noen annen løsning. «Vandrende arbeidsstasjon» mener jeg ikke
+fantes da. Dessuten ville jeg ha siste versjon, da den KDE-versjonen
+som var i Skolelinux den gangen var en god del enklere (tror det var
+KDE 2) var dårligere i mine øyne enn versjon 3.</p>
+
+<p><strong>Hvilken fri programvare bruker du til daglig?</strong></p>
+
+<p>Jeg bruker blant annet Kubuntu, LibreOffice, Thunderbird, Firefox,
+Kate, <a href="http://comix.sourceforge.net/">Comix</a> og Konsole. Og
+en hel haug andre ved behov :-)</p>
+
+<p>Har oversatt Comix selv, men det er jo ikke skjedd noe med Comix
+siden 2009, så den er det nok bare jeg som har. Om andre vil ha den
+gir jeg den gjerne videre. Ser at noen har startet på
+<a href="http://mcomix.sourceforge.net/">MComix</a> siden jeg så på så
+på dette sist, så nå er jeg igang med å teste og oversette den
+også.</p>
+
+<p><strong>Hvilken strategi tror du er den rette å bruke for å få
+skoler til å ta i bruk fri programvare?</strong></p>
+
+<p>Det viktigste er å forankre beslutningen i kollegiet og med de som
+er ansvarlige for å vedlikeholde og bruke datamaskinene. Flest mulig
+bør være med på å holde det (sosialt) vedlike, kjenne og støtte
+prinsippene. Som enkeltmannsprosjekt blir det lett veldig sårbart,
+særlig når (Skole)linux ennå i stor grad er en motkultur og ikke noe
+en stor nok andel av beslutningstakere, brukere osv kjenner til og
+bruker.</p>
+
+<p>Jeg tror det viktigste er å fortsette å holde fri programvare godt,
+oppdatert, minimere antall feil, ha en god kontakt med brukerne og
+attraktivt og spennende programmer. Beholde alt som er bra og ha det
+tilgjengelig samtidig som man tilbyr det nyeste og rareste for de som
+vil ha det.</p>
+</description>
+ </item>
+
+ <item>
+ <title>Automatic proxy configuration with Debian Edu / Skolelinux</title>
+ <link>http://people.skolelinux.org/pere/blog/Automatic_proxy_configuration_with_Debian_Edu___Skolelinux.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Automatic_proxy_configuration_with_Debian_Edu___Skolelinux.html</guid>
+ <pubDate>Mon, 13 Feb 2012 23:40:00 +0100</pubDate>
+ <description><p>New in the Squeeze version of
+<a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a> is the
+ability for clients to automatically configure their proxy settings
+based on their environment. We want all systems on the client to use
+the WPAD based proxy definition fetched from <tt>http://wpad/wpad.dat</tt>, to
+allow sites to control the proxy setting from a central place and make
+sure clients do not have hard coded proxy settings. The schools can
+change the global proxy setting by editing
+<tt>tjener:/etc/debian-edu/www/wpad.dat</tt> and the change propagate
+to all Debian Edu clients in the network.</p>
+
+<p>The problem is that some systems do not understand the WPAD system.
+In other words, how do one get from a WPAD file like this (this is a
+simple one, they can run arbitrary code):</p>
+
+<blockquote><pre>
+function FindProxyForURL(url, host)
+{
+ if (!isResolvable(host) ||
+ isPlainHostName(host) ||
+ dnsDomainIs(host, ".intern"))
+ return "DIRECT";
+ else
+ return "PROXY webcache:3128; DIRECT";
+}
+</pre></blockquote>
+
+<p>to a proxy setting in the process environment looking like this:</p>
+
+<blockquote><pre>
+http_proxy=http://webcache:3128/
+ftp_proxy=http://webcache:3128/
+</pre></blockquote>
+
+<p>To do this conversion I developed a perl script that will execute
+the javascript fragment in the WPAD file and return the proxy that
+would be used for
+<tt><a href="http://www.debian.org/">http://www.debian.org/</a></tt>,
+and insert this extracted proxy URL in <tt>/etc/environment</tt> and
+<tt>/etc/apt/apt.conf</tt>. The perl script wpad-extract work just
+fine in Squeeze, but in Wheezy the library it need to run the
+javascript code is <a href="http://bugs.debian.org/631045">no longer
+able to build</a> because the C library it depended on is now a C++
+library. I hope someone find a solution to that problem before Wheezy
+is frozen. An alternative would be for us to rewrite wpad-extract to
+use some other javascript library currently working in Wheezy, but no
+known alternative is known at the moment.</p>
+
+<p>This automatic proxy system allow the roaming workstation (aka
+laptop) setup in Debian Edu/Squeeze to use the proxy when the laptop
+is connected to the backbone network in a Debian Edu setup, and to
+automatically use any proxy present and announced using the WPAD
+feature when it is connected to other networks. And if no proxy is
+announced, direct connections will be used instead.</p>
+
+<p>Silently using a proxy announced on the network might be a privacy
+or security problem. But those controlling DHCP and DNS on a network
+could just as easily set up a transparent proxy, and force all HTTP
+and FTP connections to use a proxy anyway, so I consider that
+distinction to be academic. If you are afraid of using the wrong
+proxy, you should avoid connecting to the network in question in the
+first place. In Debian Edu, the proxy setup is updated using dhcp and
+ifupdown hooks, to make sure the configuration is updated every time
+the network setup changes.</p>
+
+<p>The WPAD system is documented in a
+<a href="http://tools.ietf.org/html/draft-ietf-wrec-wpad-01">IETF
+draft</a> and a
+<a href="http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol">Wikipedia
+page</a> for those that want to learn more.</p>
+</description>
+ </item>
+
+ <item>
+ <title>How to figure out which RAID disk to replace when it fail</title>
+ <link>http://people.skolelinux.org/pere/blog/How_to_figure_out_which_RAID_disk_to_replace_when_it_fail.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/How_to_figure_out_which_RAID_disk_to_replace_when_it_fail.html</guid>
+ <pubDate>Tue, 14 Feb 2012 21:25:00 +0100</pubDate>
+ <description><p>Once in a while my home server have disk problems. Thanks to Linux
+Software RAID, I have not lost data yet (but
+<a href="http://comments.gmane.org/gmane.linux.raid/34532">I was
+close</a> this summer :). But once a disk is starting to behave
+funny, a practical problem present itself. How to get from the Linux
+device name (like /dev/sdd) to something that can be used to identify
+the disk when the computer is turned off? In my case I have SATA
+disks with a unique ID printed on the label. All I need is a way to
+figure out how to query the disk to get the ID out.</p>
+
+<p>After fumbling a bit, I
+<a href="http://www.cyberciti.biz/faq/linux-getting-scsi-ide-harddisk-information/">found
+that hdparm -I</a> will report the disk serial number, which is
+printed on the disk label. The following (almost) one-liner can be
+used to look up the ID of all the failed disks:</p>
+
+<blockquote><pre>
+for d in $(cat /proc/mdstat |grep '(F)'|tr ' ' "\n"|grep '(F)'|cut -d\[ -f1|sort -u);
+do
+ printf "Failed disk $d: "
+ hdparm -I /dev/$d |grep 'Serial Num'
+done
+</blockquote></pre>
+
+<p>Putting it here to make sure I do not have to search for it the
+next time, and in case other find it useful.</p>
+
+<p>At the moment I have two failing disk. :(</p>
+
+<blockquote><pre>
+Failed disk sdd1: Serial Number: WD-WCASJ1860823
+Failed disk sdd2: Serial Number: WD-WCASJ1860823
+Failed disk sde2: Serial Number: WD-WCASJ1840589
+</blockquote></pre>
+
+<p>The last time I had failing disks, I added the serial number on
+labels I printed and stuck on the short sides of each disk, to be able
+to figure out which disk to take out of the box without having to
+remove each disk to look at the physical vendor label. The vendor
+label is at the top of the disk, which is hidden when the disks are
+mounted inside my box.</p>
+
+<p>I really wish the check_linux_raid Nagios plugin for checking Linux
+Software RAID in the
+<a href="http://packages.qa.debian.org/n/nagios-plugins.html">nagios-plugins-standard</a>
+debian package would look up this value automatically, as it would
+make the plugin a lot more useful when my disks fail. At the moment
+it only report a failure when there are no more spares left (it really
+should warn as soon as a disk is failing), and it do not tell me which
+disk(s) is failing when the RAID is running short on disks.</p>
</description>
</item>
projects / homepage.git / blobdiff