- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Modalias_strings___a_practical_way_to_map__stuff__to_hardware.html">Modalias strings - a practical way to map "stuff" to hardware</a></div>
- <div class="date">14th January 2013</div>
- <div class="body"><p>While looking into how to look up Debian packages based on hardware
-information, to find the packages that support a given piece of
-hardware, I refreshed my memory regarding modalias values, and decided
-to document the details. Here are my findings so far, also available
-in
-<a href="http://anonscm.debian.org/viewvc/debian-edu/trunk/src/hw-support-handler/">the
-Debian Edu subversion repository</a>:
-
-<p><strong>Modalias decoded</strong></p>
-
-<p>This document try to explain what the different types of modalias
-values stands for. It is in part based on information from
-<URL: <a href="https://wiki.archlinux.org/index.php/Modalias">https://wiki.archlinux.org/index.php/Modalias</a> >,
-<URL: <a href="http://unix.stackexchange.com/questions/26132/how-to-assign-usb-driver-to-device">http://unix.stackexchange.com/questions/26132/how-to-assign-usb-driver-to-device</a> >,
-<URL: <a href="http://code.metager.de/source/history/linux/stable/scripts/mod/file2alias.c">http://code.metager.de/source/history/linux/stable/scripts/mod/file2alias.c</a> > and
-<URL: <a href="http://cvs.savannah.gnu.org/viewvc/dmidecode/dmidecode.c?root=dmidecode&view=markup">http://cvs.savannah.gnu.org/viewvc/dmidecode/dmidecode.c?root=dmidecode&view=markup</a> >.
-
-<p>The modalias entries for a given Linux machine can be found using
-this shell script:</p>
-
-<pre>
-find /sys -name modalias -print0 | xargs -0 cat | sort -u
-</pre>
-
-<p>The supported modalias globs for a given kernel module can be found
-using modinfo:</p>
-
-<pre>
-% /sbin/modinfo psmouse | grep alias:
-alias: serio:ty05pr*id*ex*
-alias: serio:ty01pr*id*ex*
-%
-</pre>
-
-<p><strong>PCI subtype</strong></p>
-
-<p>A typical PCI entry can look like this. This is an Intel Host
-Bridge memory controller:</p>
-
-<p><blockquote>
-pci:v00008086d00002770sv00001028sd000001ADbc06sc00i00
-</blockquote></p>
-
-<p>This represent these values:</p>
-
-<pre>
- v 00008086 (vendor)
- d 00002770 (device)
- sv 00001028 (subvendor)
- sd 000001AD (subdevice)
- bc 06 (bus class)
- sc 00 (bus subclass)
- i 00 (interface)
-</pre>
-
-<p>The vendor/device values are the same values outputted from 'lspci
--n' as 8086:2770. The bus class/subclass is also shown by lspci as
-0600. The 0600 class is a host bridge. Other useful bus values are
-0300 (VGA compatible card) and 0200 (Ethernet controller).</p>
-
-<p>Not sure how to figure out the interface value, nor what it
-means.</p>
-
-<p><strong>USB subtype</strong></p>
-
-<p>Some typical USB entries can look like this. This is an internal
-USB hub in a laptop:</p>
-
-<p><blockquote>
-usb:v1D6Bp0001d0206dc09dsc00dp00ic09isc00ip00
-</blockquote></p>
-
-<p>Here is the values included in this alias:</p>
-
-<pre>
- v 1D6B (device vendor)
- p 0001 (device product)
- d 0206 (bcddevice)
- dc 09 (device class)
- dsc 00 (device subclass)
- dp 00 (device protocol)
- ic 09 (interface class)
- isc 00 (interface subclass)
- ip 00 (interface protocol)
-</pre>
-
-<p>The 0900 device class/subclass means hub. Some times the relevant
-class is in the interface class section. For a simple USB web camera,
-these alias entries show up:</p>
-
-<p><blockquote>
-usb:v0AC8p3420d5000dcEFdsc02dp01ic01isc01ip00
-<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic01isc02ip00
-<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic0Eisc01ip00
-<br>usb:v0AC8p3420d5000dcEFdsc02dp01ic0Eisc02ip00
-</blockquote></p>
-
-<p>Interface class 0E01 is video control, 0E02 is video streaming (aka
-camera), 0101 is audio control device and 0102 is audio streaming (aka
-microphone). Thus this is a camera with microphone included.</p>
-
-<p><strong>ACPI subtype</strong></p>
-
-<p>The ACPI type is used for several non-PCI/USB stuff. This is an IR
-receiver in a Thinkpad X40:</p>
-
-<p><blockquote>
-acpi:IBM0071:PNP0511:
-</blockquote></p>
-
-<p>The values between the colons are IDs.</p>
-
-<p><strong>DMI subtype</strong></p>
-
-<p>The DMI table contain lots of information about the computer case
-and model. This is an entry for a IBM Thinkpad X40, fetched from
-/sys/devices/virtual/dmi/id/modalias:</p>
-
-<p><blockquote>
-dmi:bvnIBM:bvr1UETB6WW(1.66):bd06/15/2005:svnIBM:pn2371H4G:pvrThinkPadX40:rvnIBM:rn2371H4G:rvrNotAvailable:cvnIBM:ct10:cvrNotAvailable:
-</blockquote></p>
-
-<p>The values present are</p>
-
-<pre>
- bvn IBM (BIOS vendor)
- bvr 1UETB6WW(1.66) (BIOS version)
- bd 06/15/2005 (BIOS date)
- svn IBM (system vendor)
- pn 2371H4G (product name)
- pvr ThinkPadX40 (product version)
- rvn IBM (board vendor)
- rn 2371H4G (board name)
- rvr NotAvailable (board version)
- cvn IBM (chassis vendor)
- ct 10 (chassis type)
- cvr NotAvailable (chassis version)
-</pre>
-
-<p>The chassis type 10 is Notebook. Other interesting values can be
-found in the dmidecode source:</p>
-
-<pre>
- 3 Desktop
- 4 Low Profile Desktop
- 5 Pizza Box
- 6 Mini Tower
- 7 Tower
- 8 Portable
- 9 Laptop
- 10 Notebook
- 11 Hand Held
- 12 Docking Station
- 13 All In One
- 14 Sub Notebook
- 15 Space-saving
- 16 Lunch Box
- 17 Main Server Chassis
- 18 Expansion Chassis
- 19 Sub Chassis
- 20 Bus Expansion Chassis
- 21 Peripheral Chassis
- 22 RAID Chassis
- 23 Rack Mount Chassis
- 24 Sealed-case PC
- 25 Multi-system
- 26 CompactPCI
- 27 AdvancedTCA
- 28 Blade
- 29 Blade Enclosing
-</pre>
-
-<p>The chassis type values are not always accurately set in the DMI
-table. For example my home server is a tower, but the DMI modalias
-claim it is a desktop.</p>
-
-<p><strong>SerIO subtype</strong></p>
-
-<p>This type is used for PS/2 mouse plugs. One example is from my
-test machine:</p>
-
-<p><blockquote>
-serio:ty01pr00id00ex00
-</blockquote></p>
-
-<p>The values present are</p>
-
-<pre>
- ty 01 (type)
- pr 00 (prototype)
- id 00 (id)
- ex 00 (extra)
-</pre>
-
-<p>This type is supported by the psmouse driver. I am not sure what
-the valid values are.</p>
-
-<p><strong>Other subtypes</strong></p>
-
-<p>There are heaps of other modalias subtypes according to
-file2alias.c. There is the rest of the list from that source: amba,
-ap, bcma, ccw, css, eisa, hid, i2c, ieee1394, input, ipack, isapnp,
-mdio, of, parisc, pcmcia, platform, scsi, sdio, spi, ssb, vio, virtio,
-vmbus, x86cpu and zorro. I did not spend time documenting all of
-these, as they do not seem relevant for my intended use with mapping
-hardware to packages when new stuff is inserted during run time.</p>
-
-<p><strong>Looking up kernel modules using modalias values</strong></p>
-
-<p>To check which kernel modules provide support for a given modalias,
-one can use the following shell script:</p>
-
-<pre>
- for id in $(find /sys -name modalias -print0 | xargs -0 cat | sort -u); do \
- echo "$id" ; \
- /sbin/modprobe --show-depends "$id"|sed 's/^/ /' ; \
- done
-</pre>
-
-<p>The output can look like this (only the first few entries as the
-list is very long on my test machine):</p>
-
-<pre>
- acpi:ACPI0003:
- insmod /lib/modules/2.6.32-5-686/kernel/drivers/acpi/ac.ko
- acpi:device:
- FATAL: Module acpi:device: not found.
- acpi:IBM0068:
- insmod /lib/modules/2.6.32-5-686/kernel/drivers/char/nvram.ko
- insmod /lib/modules/2.6.32-5-686/kernel/drivers/leds/led-class.ko
- insmod /lib/modules/2.6.32-5-686/kernel/net/rfkill/rfkill.ko
- insmod /lib/modules/2.6.32-5-686/kernel/drivers/platform/x86/thinkpad_acpi.ko
- acpi:IBM0071:PNP0511:
- insmod /lib/modules/2.6.32-5-686/kernel/lib/crc-ccitt.ko
- insmod /lib/modules/2.6.32-5-686/kernel/net/irda/irda.ko
- insmod /lib/modules/2.6.32-5-686/kernel/drivers/net/irda/nsc-ircc.ko
- [...]
-</pre>
-
-<p>If you want to help implementing a system to let us propose what
-packages to install when new hardware is plugged into a Debian
-machine, please send me an email or talk to me on
-<a href="irc://irc.debian.org/%23debian-devel">#debian-devel</a>.</p>
-
-<p><strong>Update 2013-01-15:</strong> Rewrite "cat $(find ...)" to
-"find ... -print0 | xargs -0 cat" to make sure it handle directories
-in /sys/ with space in them.</p>
+ <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 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>
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