Some further experimentation has revealed that the issue may be with the drive Advanced Power Management function.
When operating on AC power, "hdparm -B /dev/sda" gives APM_level = 254 A few seconds after removing AC power, "hdparm -B /dev/sda" gives APM_level = 127 Running like this for a few minutes (generally anything between 30 seconds and 10 minutes) results in the above ATA errors. Executing "hdparm -B 254 /dev/sda" after unplugging AC power appears to prevent the errors appearing. This isn't ideal as it means the disk won't spin down (I think it may hae implications relating to disk head parking too though I don't know enough about this). Plugging AC power back in then removing it sets APM_level back to 127, so in the absence of a fix for the ATA errors at APM_level 127, at the very least I need to find out how to prevent APM_level being set to 127 on removal of power. Again - this did not occur with Ubuntu 11.x or Fedora 16 & 17 Beta 2. Today I tried mainline kernel 3.4.0 rc5 (dated May 1st 2012) which also exhibits the same symptoms. Any suggestions? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/984308 Title: ATA failures when operating on battery power in Ubuntu 12.04 To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/984308/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
