[Wylug-help] Raid problem

[Roger]

Steven Dodd wrote:
> On 24/04/07 13:18, Roger Beaumont wrote:
<snip>
>> 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.

That's greek to me I'm afraid...

> Is md9 mentioned at all in the boot messages (dmesg)? 

Dunno.  I don't remember seeing it flash past...  Where do I find dmesg?

> What command line
> did you use to create the array and then to assemble it after a boot?

to create (as far as I can remember):

$ mdadm -C /dev/md9 -l1 -n2 /dev/sda /dev/sdb

to assemble:

$ mdadm -A /dev/md9 -amd --run /dev/mda

then:

$ mdadm /dev/md9 -a /dev/mdb

On the occasion I tried to assemble both devices at once instead of 
assmbling with one, then adding the other, the box hung immediately, so 
I haven't done that since.

Roger