SSD installation checklist

IMPORTANT NOTE: This document was initially written around November 2010 when SSD support was still considered recent in GNU/Linux distributions and Ubuntu in general. Be careful when deciding to apply any of the information it contains.

A few assumptions are made in this list:

• /dev/sda is your SSD device

• Performance is preferred to reliability. Therefore, you backup regularly or use this for non-critical (even expendable) data.
• You already have a backup of any important data (can't stress this enough).

If you contribute something to this list, please make sure whatever it is has a justification, explanation, reference, or all three.

Ubuntu 10.10

• Check for firmware upgrades for your drive and apply any pending.
  $ sudo hdparm -I /dev/sda | grep Firmware
  Firmware Revision:  2CV102M3
  Bugs #663349 and #672764 have been filed about lshw and udev, mark those as affecting you if you wish so. Once you know your firmware version, go to your manufacturer's site:

  • Intel SSD firmware updates

  • RunCore SSD firmware updates & http://www.corsair.com/support/faq/solid-state-drives/#answer1 Corsair FAQ on firmware updates

  • ...
• Boot from a Live CD

  • Find out your hard disk information with sudo fdisk -l /dev/sda | grep sectors. Example output:
    255 heads, 63 sectors/track, 4865 cylinders

  • Partition & format your disk aligning the partition blocksize to the SSD erase block size, with the above information (1 partition, no swap, no journaling ext4):
    sudo fdisk -H 255 -S 63 /dev/sda
    sudo mke2fs -t ext4 -O ^has_journal /dev/sda1
    

Warning: formatting without journaling will increase chances of data loss. Use with caution. Omit the -O ^has_journal option otherwise. The Linux Documentation Project has complete information about fdisk partitioning.

• Make sure SATA AHCI mode is enabled in BIOS. See SATA AHCI Mode Bios Setting. What Does it do?

• Reboot the the Alternate Ubuntu installer CD, install normally - use manual partitioning though, mounting / to your single partition, accepting warnings about swap not being present.
• Kernel boot options:
  • Change the I/O scheduler to NOOP:

    • If you only have one disk and it is SSD, and don't use external storage often, just add elevator=noop to your kernel boot parameters in /etc/default/grub (append to GRUB_CMDLINE_LINUX_DEFAULT). This is also OK if you occasionally use USB sticks.

    • If you have several disks or a mix of SSD and mechanical disks, install the sysfsutils package and add the following line at the end of /etc/sysfs.conf:
      block/sda/queue/scheduler = noop

    • To change the scheduler without rebooting:
      sudo echo noop > /sys/block/sda/queue/scheduler

• Disk mounting options (in /etc/fstab):

  • Example mounting line:
    UUID=41b6b187-be76-4447-b18b-d39cc744b184 /               ext4    noatime,discard,data=writeback,errors=remount-ro 0       1

  • Add the noatime mounting option. The default is relatime which adds write operations to set the Last Accessed Time attribute to files.

  • Add the discard mounting option. This controls whether ext4 should issue discard/TRIM commands to the underlying block device when blocks are freed. This is useful for SSD devices and sparse/thinly-provisioned LUNs, but it is off by default until sufficient testing has been done.

  • Add the data=writeback mounting option if you formatted the disk without journaling. Otherwise add data=ordered which sould be a good compromise between full journaling and none at all. See Ext4 Filesystem documentation for more details.

Other considerations:

• Mount /tmp in ram

  • Use the following line in /etc/fstab and reboot:
    tmpfs   /tmp  tmpfs  nodev,nosuid,noexec,mode=1777  0 0
    Rationale: In the past when SSD controllers had bad wear leveling and limited amounts of writes, mounting anything that was often wrote to (like /tmp) was a good idea. Nowadays it helps with performance but also as some caveats.

• Put the Firefox cache in /tmp (which is in RAM)

  • Type about:config in the location bar

  • Find/create this key: browser.cache.disk.parent_directory. Set it to /tmp

  • Verify the cache location information in about:cache

* Pros:

• Placing your browser cache in /tmp, and mounting /tmp in RAM is a sure boost to page rendering.

* Cons:

• Do only with at least 4Gb of RAM
• Watch for GUI apps (disc burners etc) writing large files to /tmp
• In multi-user systems if other users are logged in they will have access to your temporary files in /tmp

Reference links

• http://ubuntuforums.org/showthread.php?t=1041524

• http://www.zdnet.com/blog/perlow/geek-sheet-a-tweakers-guide-to-solid-state-drives-ssds-and-linux/9190

• http://www.linuxhowtos.org/System/iosched.htm - including information on how to change the I/O scheduler at runtime