X-Git-Url: https://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/ee7863aa4a356a09164265e19eed3a9ab9bafff1..ddcfad7e9db9d6a3bd5159b590658f7b06eb48cb:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index e6229f4cbf..252ae36d1b 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -6,6 +6,34 @@ http://people.skolelinux.org/pere/blog/ + + Skolelinux / Debian Edu 7.1 install and overview video from Marcelo Salvador + http://people.skolelinux.org/pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html + http://people.skolelinux.org/pere/blog/Skolelinux___Debian_Edu_7_1_install_and_overview_video_from_Marcelo_Salvador.html + Tue, 8 Oct 2013 17:10:00 +0200 + <p>The other day I was pleased and surprised to discover that Marcelo +Salvador had published a +<ahref="https://www.youtube.com/watch?v=w-GgpdqgLFc">video on +Youtube</a> showing how to install the standalone Debian Edu / +Skolelinux profile. This is the profile intended for use at home or +on laptops that should not be integrated into the provided network +services (no central home directory, no Kerberos / LDAP directory etc, +in other word a single user machine). The result is 11 minutes long, +and show some user applications (seem to be rather randomly picked). +Missed a few of my favorites like celestia, planets and chromium +showing the <ahref="http://www.zygotebody.com/no_webgl.html">Zygote +Body 3D model of the human body</a>, but I guess he did not know about +those or find other programs more interesting. :)</p> + +<p>Anyway, check out the video, embedded below and linked to above:</p> + +<iframe width="420" height="315" src="http://www.youtube.com/embed/w-GgpdqgLFc" frameborder="0" allowfullscreen></iframe> + +<p>Are there other nice videos demonstrating Skolelinux? Please let +me know. :)</p> + + + Finally, Debian Edu Wheezy is released today! http://people.skolelinux.org/pere/blog/Finally__Debian_Edu_Wheezy_is_released_today_.html @@ -959,112 +987,5 @@ release.</p> - - How to fix a Thinkpad X230 with a broken 180 GB SSD disk - http://people.skolelinux.org/pere/blog/How_to_fix_a_Thinkpad_X230_with_a_broken_180_GB_SSD_disk.html - http://people.skolelinux.org/pere/blog/How_to_fix_a_Thinkpad_X230_with_a_broken_180_GB_SSD_disk.html - Wed, 17 Jul 2013 23:50:00 +0200 - <p>Today I switched to -<a href="http://people.skolelinux.org/pere/blog/The_Thinkpad_is_dead__long_live_the_Thinkpad_X230_.html">my -new laptop</a>. I've previously written about the problems I had with -my new Thinkpad X230, which was delivered with an -<a href="http://people.skolelinux.org/pere/blog/Intel_SSD_520_Series_180_GB_with_Lenovo_firmware_still_lock_up_from_sustained_writes.html">180 -GB Intel SSD disk with Lenovo firmware</a> that did not handle -sustained writes. My hardware supplier have been very forthcoming in -trying to find a solution, and after first trying with another -identical 180 GB disks they decided to send me a 256 GB Samsung SSD -disk instead to fix it once and for all. The Samsung disk survived -the installation of Debian with encrypted disks (filling the disk with -random data during installation killed the first two), and I thus -decided to trust it with my data. I have installed it as a Debian Edu -Wheezy roaming workstation hooked up with my Debian Edu Squeeze main -server at home using Kerberos and LDAP, and will use it as my work -station from now on.</p> - -<p>As this is a solid state disk with no moving parts, I believe the -Debian Wheezy default installation need to be tuned a bit to increase -performance and increase life time of the disk. The Linux kernel and -user space applications do not yet adjust automatically to such -environment. To make it easier for my self, I created a draft Debian -package <tt>ssd-setup</tt> to handle this tuning. The -<a href="http://anonscm.debian.org/gitweb/?p=collab-maint/ssd-setup.git">source -for the ssd-setup package</a> is available from collab-maint, and it -is set up to adjust the setup of the machine by just installing the -package. If there is any non-SSD disk in the machine, the package -will refuse to install, as I did not try to write any logic to sort -file systems in SSD and non-SSD file systems.</p> - -<p>I consider the package a draft, as I am a bit unsure how to best -set up Debian Wheezy with an SSD. It is adjusted to my use case, -where I set up the machine with one large encrypted partition (in -addition to /boot), put LVM on top of this and set up partitions on -top of this again. See the README file in the package source for the -references I used to pick the settings. At the moment these -parameters are tuned:</p> - -<ul> - -<li>Set up cryptsetup to pass TRIM commands to the physical disk - (adding discard to /etc/crypttab)</li> - -<li>Set up LVM to pass on TRIM commands to the underlying device (in - this case a cryptsetup partition) by changing issue_discards from - 0 to 1 in /etc/lvm/lvm.conf.</li> - -<li>Set relatime as a file system option for ext3 and ext4 file - systems.</li> - -<li>Tell swap to use TRIM commands by adding 'discard' to - /etc/fstab.</li> - -<li>Change I/O scheduler from cfq to deadline using a udev rule.</li> - -<li>Run fstrim on every ext3 and ext4 file system every night (from - cron.daily).</li> - -<li>Adjust sysctl values vm.swappiness to 1 and vm.vfs_cache_pressure - to 50 to reduce the kernel eagerness to swap out processes.</li> - -</ul> - -<p>During installation, I cancelled the part where the installer fill -the disk with random data, as this would kill the SSD performance for -little gain. My goal with the encrypted file system is to ensure -those stealing my laptop end up with a brick and not a working -computer. I have no hope in keeping the really resourceful people -from getting the data on the disk (see -<a href="http://xkcd.com/538/">XKCD #538</a> for an explanation why). -Thus I concluded that adding the discard option to crypttab is the -right thing to do.</p> - -<p>I considered using the noop I/O scheduler, as several recommended -it for SSD, but others recommended deadline and a benchmark I found -indicated that deadline might be better for interactive use.</p> - -<p>I also considered using the 'discard' file system option for ext3 -and ext4, but read that it would give a performance hit ever time a -file is removed, and thought it best to that that slowdown once a day -instead of during my work.</p> - -<p>My package do not set up tmpfs on /var/run, /var/lock and /tmp, as -this is already done by Debian Edu.</p> - -<p>I have not yet started on the user space tuning. I expect -iceweasel need some tuning, and perhaps other applications too, but -have not yet had time to investigate those parts.</p> - -<p>The package should work on Ubuntu too, but I have not yet tested it -there.</p> - -<p>As for the answer to the question in the title of this blog post, -as far as I know, the only solution I know about is to replace the -disk. It might be possible to flash it with Intel firmware instead of -the Lenovo firmware. But I have not tried and did not want to do so -without approval from Lenovo as I wanted to keep the warranty on the -disk until a solution was found and they wanted the broken disks -back.</p> - - -