Boon is a dual boot desktop machine with an old, mostly unused copy of XP in one partition and a LVM of rotating Linux distributions, currently Ubuntu 10.04. This machine is kind of cranky and doesn’t like being left on all day. Sunday I left it on all day. When I came back to it that evening, it had locked up. I rebooted and got a kernel oops. This morning I tried diagnosing the problem. The current version of Linux failed to boot. The prior version also failed. And the rescue version failed. The kernel oops listed an IO error, so I suspected a problem with the suspend image stored in the swap partition. (This machine is normally suspended rather than powered off.)
I started SystemRescueCD and it was just fine. So no memory or CPU problems. I ran vgdisplay to see the volume groups. I was able to mount the root and home partitions and they looked OK. In the root partition, I looked in etc/fstab to see where the swap partition was. It was referenced by a UUID. To check, I tried mounting that UUID and confirmed that mount saw it as a swap partition. To get rid of the suspend image, I ran mkswap on /dev/disk/by-uuid/
After a reboot it’s back up!