+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/How_to_fix_a_Thinkpad_X230_with_a_broken_180_GB_SSD_disk.html">How to fix a Thinkpad X230 with a broken 180 GB SSD disk</a></div>
+ <div class="date">17th July 2013</div>
+ <div class="body"><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 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>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title"><a href="http://people.skolelinux.org/pere/blog/Intel_SSD_520_Series_180_GB_with_Lenovo_firmware_still_lock_up_from_sustained_writes.html">Intel SSD 520 Series 180 GB with Lenovo firmware still lock up from sustained writes</a></div>
<div class="date">10th July 2013</div>
</div>
<div class="padding"></div>
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Fixing_the_Linux_black_screen_of_death_on_machines_with_Intel_HD_video.html">Fixing the Linux black screen of death on machines with Intel HD video</a></div>
- <div class="date">11th June 2013</div>
- <div class="body"><p>When installing RedHat, Fedora, Debian and Ubuntu on some machines,
-the screen just turn black when Linux boot, either during installation
-or on first boot from the hard disk. I've seen it once in a while the
-last few years, but only recently understood the cause. I've seen it
-on HP laptops, and on my latest acquaintance the Packard Bell laptop.
-The reason seem to be in the wiring of some laptops. The system to
-control the screen background light is inverted, so when Linux try to
-turn the brightness fully on, it end up turning it off instead. I do
-not know which Linux drivers are affected, but this post is about the
-i915 driver used by the
-<a href="http://www.linlap.com/packard_bell_easynote_lv">Packard Bell
-EasyNote LV</a>, Thinkpad X40 and many other laptops.</p>
-
-<p>The problem can be worked around two ways. Either by adding
-i915.invert_brightness=1 as a kernel option, or by adding a file in
-/etc/modprobe.d/ to tell modprobe to add the invert_brightness=1
-option when it load the i915 kernel module. On Debian and Ubuntu, it
-can be done by running these commands as root:</p>
-
-<pre>
-echo options i915 invert_brightness=1 | tee /etc/modprobe.d/i915.conf
-update-initramfs -u -k all
-</pre>
-
-<p>Since March 2012 there is
-<a href="http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4dca20efb1a9c2efefc28ad2867e5d6c3f5e1955">a
-mechanism in the Linux kernel</a> to tell the i915 driver which
-hardware have this problem, and get the driver to invert the
-brightness setting automatically. To use it, one need to add a row in
-<a href="http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/i915/intel_display.c">the
-intel_quirks array</a> in the driver source
-<tt>drivers/gpu/drm/i915/intel_display.c</tt> (look for "<tt>static
-struct intel_quirk intel_quirks</tt>"), specifying the PCI device
-number (vendor number 8086 is assumed) and subdevice vendor and device
-number.</p>
-
-<p>My Packard Bell EasyNote LV got this output from <tt>lspci
--vvnn</tt> for the video card in question:</p>
-
-<p><pre>
-00:02.0 VGA compatible controller [0300]: Intel Corporation \
- 3rd Gen Core processor Graphics Controller [8086:0156] \
- (rev 09) (prog-if 00 [VGA controller])
- Subsystem: Acer Incorporated [ALI] Device [1025:0688]
- Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- \
- ParErr- Stepping- SE RR- FastB2B- DisINTx+
- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- \
- <TAbort- <MAbort->SERR- <PERR- INTx-
- Latency: 0
- Interrupt: pin A routed to IRQ 42
- Region 0: Memory at c2000000 (64-bit, non-prefetchable) [size=4M]
- Region 2: Memory at b0000000 (64-bit, prefetchable) [size=256M]
- Region 4: I/O ports at 4000 [size=64]
- Expansion ROM at <unassigned> [disabled]
- Capabilities: <access denied>
- Kernel driver in use: i915
-</pre></p>
-
-<p>The resulting intel_quirks entry would then look like this:</p>
-
-<p><pre>
-struct intel_quirk intel_quirks[] = {
- ...
- /* Packard Bell EasyNote LV11HC needs invert brightness quirk */
- { 0x0156, 0x1025, 0x0688, quirk_invert_brightness },
- ...
-}
-</pre></p>
-
-<p>According to the kernel module instructions (as seen using
-<tt>modinfo i915</tt>), information about hardware needing the
-invert_brightness flag should be sent to the
-<a href="http://lists.freedesktop.org/mailman/listinfo/dri-devel">dri-devel
-(at) lists.freedesktop.org</a> mailing list to reach the kernel
-developers. But my email about the laptop sent 2013-06-03 have not
-yet shown up in
-<a href="http://lists.freedesktop.org/archives/dri-devel/2013-June/thread.html">the
-web archive for the mailing list</a>, so I suspect they do not accept
-emails from non-subscribers. Because of this, I sent my patch also to
-the Debian bug tracking system instead as
-<a href="http://bugs.debian.org/710938">BTS report #710938</a>, to make
-sure the patch is not lost.</p>
-
-<p>Unfortunately, it is not enough to fix the kernel to get Laptops
-with this problem working properly with Linux. If you use Gnome, your
-worries should be over at this point. But if you use KDE, there is
-something in KDE ignoring the invert_brightness setting and turning on
-the screen during login. I've reported it to Debian as
-<a href="http://bugs.debian.org/711237">BTS report #711237</a>, and
-have no idea yet how to figure out exactly what subsystem is doing
-this. Perhaps you can help? Perhaps you know what the Gnome
-developers did to handle this, and this can give a clue to the KDE
-developers? Or you know where in KDE the screen brightness is changed
-during login? If so, please update the BTS report (or get in touch if
-you do not know how to update BTS).</p>
-</div>
- <div class="tags">
-
-
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
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