Comment 22 for bug 120375

Jan Krupa (plnt) wrote :


The problem can be workarounded by issuing this command on the BusyBox shell when Ubuntu is missing one of the RAID disks:

/sbin/mdadm --assemble --scan

+ reboot

It will remove the missing disk from RAID 1 and allow Ubuntu to boot in degraded mode next time.

I think the root cause of the problem is in forcing mdadm not to start in degraded mode by "--no-degraded" parameter in /etc/udev/rules.d/85-mdadm.rules. If you remove "--no-degraded" parameter from mdadm in /etc/udev/rules.d/85-mdadm.rules and rerun "sudo update-initramfs -u", Ubuntu doesn't refuse to boot even if one of the disks is missing (after this change, no workarounds are needed). The problem is that it starts in degraded mode in some cases even if both disks are present.

Tested on Ubuntu/Gutsy.

I appreciate any comments.