Running Ubuntu on a Toshiba Z830

I bought a Toshiba Z830 recently.  This post is to document how I am running Kubuntu on it.  First, let me show you how fast it boots :)

1. The machine has only 128GB storage, which cannot be upgraded yet, which means having both Windows and Linux on the machine may not be realistic.  But there’s a way to back up Windows!  Toshiba bundles a program with the computer that creates recovery USB drives for the Z830.  I bought a new 16GB USB drive and made it a recovery drive.  The plan is to use this for restoring Windows when I am giving this laptop away to somebody in future.
2. I downloaded 64-bit Kubuntu 11.10 installer from kubuntu.org.  Since I have a backup copy of Windows, I removed all NTFS and recovery partitions from the disk and created new partitions for installing Kubuntu.
3. After the installation, almost everything worked out of the box.  I had no issues with the laptop sleeping or waking up; 3D graphics worked fine; audio, bluetooth, webcam... everything worked.  Except the following one issue.
4. Screen brightness controls sometimes worked, but sometimes they didn’t.  The technique that helped in 2008 helped me this time too, except I needed to make a minor modification to the program: the file that required changing was /sys/class/backlight/intel_backlight/brightness (i.e. intel_backlight instead of acpi_video0).  And the brightness value seem to be in the range of 100 through 4400.
5. Battery life was bad.  More worrying than battery life was the heat generated by the laptop.  I found some tips to reduce power usage on Putokaz blog, and tried it (thank you, voloder!).  While it did reduce power consumption, it also resulted in some screen update issues.  After some trial and error, I found that frame buffer compression was causing issues, so I left that one out.
   Update: Kubuntu 12.04 provides a very good battery life out of the box.
6. ZDNet recommends disabling “elevator” I/O scheduler by passing elevator=noop to kernel.  Based on tips from both sources, I have updated my /etc/default/grub to have this line:
   

   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash elevator=noop"
   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force i915.i915_enable_rc6=1 i915.lvds_downclock=1 elevator=noop"

   (Power management flags may work on other computers with the same Core i5-2467M Sandy Bridge processor as well.)
7. Based on the same ZDNet story mentioned before, I updated my /etc/fstab as well.  I added noatime flag to my ext4 partitions and mounted /tmp on RAM using tmpfs.  (I didn’t change the caching parameters as that sounds a bit scary.)

   UUID=dbccce1d-8e31-428e-a25a-227afc54651f /      ext4  noatime  0  1
   UUID=720c576c-2c1a-435f-ae90-9151acda2005 /home  ext4  noatime  0  2
   tmpfs /tmp tmpfs nodev,nosuid,noexec,size=1G 0 0
   

Update: Someone was asking about battery life, so here's a screenshot of expected battery life.  With Ubuntu 12.04, you'd get more than 5 hours of battery life on a full charge.