md raid 5 not working
Kanwar Ranbir Sandhu
m3freak at thesandhufamily.ca
Sun Dec 27 00:02:42 UTC 2009
On Sat, 2009-12-26 at 15:28 -0500, Kanwar Ranbir Sandhu wrote:
> My Linux RAID skills/experience aren't that deep, so I'm not sure how to
> fix this. I'd appreciate any pointers.
>
> Some details:
> Device Boot Start End Blocks Id System
> /dev/sdb1 1 60801 488384001 fd Linux raid autodetect
> Device Boot Start End Blocks Id System
> /dev/sdd1 1 60801 488384001 fd Linux raid autodetect
> Device Boot Start End Blocks Id System
> /dev/sde1 1 60801 488384001 fd Linux raid autodetect
Solved my problem!
As you can see here, the md superblock is on the first primary partition
of each of these drives. But, Linux wasn't seeing these partitions. A
simple 'ls -l /dev/sd*' only showed me /dev/sdb, /dev/sdd, and /dev/sde.
The reason I provided mdadm details on these drives was because I
couldn't see /dev/sdb1, etc. I couldn't give md information on the
partitions.
I realized I had once used the entire drives in a md RAID 5 set instead
of building the RAID 5 on partitions. I had outdated md superblocks
on /dev/sd[bde]! I suppose when I rebuilt the array properly, I didn't
wipe the drives completely. Basically, the old md superblocks were
confusing the kernel.
To fix this, I ran the following from the rescue CD:
mdadm --zero-superblock --force /dev/sdb
mdadm --zero-superblock --force /dev/sdd
mdadm --zero-superblock --force /dev/sde
When I rebooted, /dev/md3 was detected properly and came up without any
problems. Sweet!
Thanks to everyone that replied. I didn't think I could solve this one
on my own, but the man page + my realization of what was going on helped
immensely.
Regards,
Ranbir
More information about the fedora-list
mailing list