[Wylug-help] Raid problem

[Steven Dodd]

On 24/04/07 13:18, Roger Beaumont wrote:
> I have a small network at home with a server-box that (amongst other
> jobs) acts as a file-server.
> 
> Naturally, the existing disks (190GB, RAID 1) filled up so I've added a
> SATA card and 2 Seagate 250's (sda & sdb), each partitioned as single,
> 'fd' partitions, then 'mdadm'ed together as /dev/md9 (another mirror
> array) with an ext3 filesystem.
> 
> So far so good - after 3 hours synching it's all up and running, with
> md9 mounted temporarily on /newraid so I can copy the files from
> /space/shares/data/ onto it.
> 
> Then something hangs the box (or I 'init 6') and while md0 to md8
> reactivate just like they always have, /dev/md9 has disappeared ['no
> such file'], so I have to reassemble the raid and remount (and there's
> another 3 hour re-synch until the data's all secure again).
> 
> At one stage I made the mistake of adding md9 to fstab - which meant
> that the boot process aborted because /dev/md9 wasn't found, and until I
> worked out what I was looking for and found mount -o remount, the whole
> box was down.
> 
> If I'm right, the first thing to fix is the problem that /dev/md9
> disappears on re-boot.  Anybody know why, and how to stop that happening?
> 

If you'd created it with raidtools and /etc/raidtab, I'd say you
probably forgot to specify "persistent-superblock".  Not sure if there
is any equivalent with mdadm, or if it always creates arrays that way
anyway.

Is md9 mentioned at all in the boot messages (dmesg)?  What command line
did you use to create the array and then to assemble it after a boot?

-Steve.