From the Canyon Edge -- :-Dustin

Wednesday, October 29, 2008

Booting Degraded RAID in Hardy: Test Packages in my PPA

We have significantly improved booting on degraded software RAID in Ubuntu Intrepid Ibex.

Numerous Hardy users have requested a backport of this functionality to Ubuntu 8.04 LTS.

I'm pleased to announce that I have some very preliminary, working packages in my PPA, available for testing. See:
A couple of caveats...
  1. Under no circumstances should these packages be used on any production-level, critical, or enterprise system.
  2. These packages are not officially supported by Canonical, Ubuntu, or even really me.
  3. These packages are provided exclusively for the sake of testing and debugging the functionality in advance of an official update being published.
That said, if you have some spare hardware or virtualization at your disposal, and you're willing and able to test these packages on a non-critical development/test system, I would appreciate hearing your experience.

The test case is essentially as follows:
  1. Install Ubuntu 8.04.1 LTS (Hardy Heron) onto a software RAID1 configuration
  2. Update your package list, upgrade all packages, dist-upgrade, and reboot
  3. Add my PPA to your /etc/apt/sources.list, update your package list, and pull my updated Hardy packages
  4. Re-install grub to your RAID device, "grub-install /dev/md0" or whatever might be appropriate
  5. Reboot with both disks (ensure this continues to work)
  6. Reboot, with only the first of the two disks (you should be prompted if you'd like to boot or not; first test answering "No"; reboot and test answering "Yes")
  7. Reboot with only the second of the two disks, and again test both the "No" and "Yes" behavior
  8. Reboot with both disks attached, and one disk should be "missing" from the array since they are now out of sync, having each been booted independently. Add the missing disk back to the array with something like "mdadm /dev/md0 --add /dev/sdb1", and let it re-sync.
If the above succeeded as expected, I'd like to hear about it. If it didn't, I'd also like to hear about it. Please post as comments to this bug report: