[mythtv-users] Rebuild raid array ?

[Jean-Yves Avenard]

Hi

On 21 November 2010 12:08, Kevin Bailey <keraba at gmail.com> wrote:
> Seasons greetings, all,
> Long time, no see. I've been enjoying 0.22 so much that I fell off the
> mailing list.
> Now I'm trying to upgrade to 0.24 and ran into some (albeit non-mythtv)
> trouble.
> But I suspect others on the list have some experience here, so crossing my
> fingers.
> I figured it was also time to upgrade the server to Lucid. This appeared to
> go ok.
> When I rebooted, it refused to mount my RAID array. For reference, here's
> what I have:
> sda1: boot partition
> sda2: RAID
> sdb1: swap
> sdb2: RAID
> sdc1: swap
> sdc2: RAID
> sdd1: swap
> sdd2: RAID
> I booted from a Lucid CD, and ran mdadm --assemble /dev/md0, and it said:
> mdadm: failed to add /dev/sda2 to /dev/md0: Device or resource busy
> mdadm: /dev/md0 has been started with 3 drives (out of 4).
> Looking at dmesg, it says:
> [    5.975166] EXT3-fs (sda1): mounted filesystem with ordered data mode
> [    6.044417] EXT3-fs error (device sda2): ext3_check_descriptors: Block
> bitmap for group 1920 not in group (block 32832)!
> [    6.044423] EXT3-fs (sda2): error: group descriptors corrupted
> [    6.330151] EXT4-fs (sdd2): Couldn't mount because of unsupported
> optional features (4000000)
> /proc/mdstat says:
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 sda2[4] sdd2[3] sdc2[2] sdb2[1]
>       729599808 blocks level 5, 64k chunk, algorithm 2 [4/3] [_UUU]
>       [===================>.]  recovery = 99.0% (240874624/243199936)
> finish=0.6min speed=56580K/sec
>
> unused devices: <none>
> At this point, I *could* just copy everything off and start from ground
> zero,
> but I think you all know what a pain in the back-end that would be, and
> I have this tiny suspicion that there's something I could do to make
> it happy again.
> Would some kind soul suggest some things I could try to bring back my myth
> server ?
> Thanks!

md has always been happier with entire disks.

Why don't just just remove sdd2 from the array, format it, re-add it
and let md rebuild the array?

JY