Using Ubuntu 11.04 (latest patched)
I have 5 RAID-1 file systems that are automatically assembled during the boot process
(Note: none of the system FS
/usr... are raid, only user FSes).
Once in a while, during boot, an MD cannot be assembled (seemingly) and Ubuntu asks
(edit: exact message)
The disk drive for '/home/development' is not ready yet or is not present. You may keep waiting; Skip the drive; Manual recovery
But the FS will never be ready. After a reboot, it usually becomes available.
It happens sometimes - not always the same MD - I saw quickly that a FS was being checked just before it happened today.
It seems to be a kind of race condition between
mdadm and the FS checking system, and this would be a bug IMO.
edit It happens sometimes, even if no FS was being checked...
ARRAY /dev/md0 level=raid1 num-devices=2 metadata=00.90 UUID=121f2e3b:415a1234:abcdb5ce:5f9876d3 ...
/dev/md0 /home/development ext4 defaults,relatime 1 2 ...
Edit Feb 2012
I don't think it is a bug per se. Even in Ubuntu 11.10 (latest as of today) the problem persists (and none of my drives / FS are corrupted).
It is very likely to be related to the rc.d order of operations.
It seems the drives are still being checked, or are not ready yet for some reasons, while
mdadm tries - too early - to make the associations between the two disks, and fails.
Any new idea is welcome.