Hi everybody, I wanted to share the solution to a problem I had today...
I had one of my computers unable to boot, after a software upgrade followed by reboot. Dracut was complaining about things, the message looked something like
no root device "block:/dev/mapper/volgroup-lv_root" found
then dropped to some very useless shell. I followed the advice on this page about changing grub params, but it never got me anywhere. Using a bootable USB key with fedora, I couldn't even mount the boot partition, in my case /dev/sda1. The error was something like "partition busy or already mounted". That's what finally let me to my solution. Somebody else with the same problem online used this command (in my case run from the USB key fedora)
dmraid -r -E
and the computer just magically rebooted fine! Presumably a yum upgrade on dmraid was the cause of the problem, and it had nothing to do with dracut... My machine does have RAID disks, this solution is obviously only relevant to people with RAID. I thought I'd share this in case other people had the same problem.