How do you ensure Grub is properly installed on a software RAID array in Ubuntu?
I have a failed RAID array on an Ubuntu 14.04 server. When I first tried booting it, the Grub screen came up, but selecting any kernel resulted in an endless stream of system messages, and I never got to login prompt. Selecting a recovery kernel to boot, I was able to select the "enable networking" option, which mounted the array and gave me a login prompt, but now I'm trying to get it to boot normally.
Following the instructions here I ensured mdadm
was configured correctly to use BOOT_DEGRADED=true
. However, when I run:
sudo grub-install /dev/md0
or:
sudo grub-install /dev/md1
I get the error:
Installing for i386-pc platform.
grub-install: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image..
grub-install: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image..
grub-install: error: unable to identify a filesystem in mduuid/ca0a39c0c1a9dada1aa912e49b297d06; safety check can't be performed.
Why is grub-install
failing? Is this normal because one of the drives has failed, or is my RAID array misconfigured? How do I ensure it'll boot with just a single drive?