On Mon, 2 Apr 2012, Wayne Johnson wrote:
> cat /proc/mdstat
> is your best friend when running mdm raid. It tells you the current state of each "drive" as well as the state of the components.
>
>
> Example from my machine:
> Personalities : [raid1]
> md0 : active raid1 sda3[1]
> 243175808 blocks [2/1] [_U]
>
> unused devices: <none>
>
> I have one raid one device, md0. It has one dead device (the _).
Here's what my messed-up machine is showing:
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda2[0]
8200960 blocks [2/1] [U_]
md0 : active raid1 sda1[0]
1945312384 blocks [2/1] [U_]
unused devices: <none>
Here's what my other (probably OK) machine is showing:
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sdb3[1] sda3[0]
241641600 blocks [2/2] [UU]
md0 : active raid1 sdb1[1] sda1[0]
497856 blocks [2/2] [UU]
unused devices: <none>
I think I'm starting to understand this a little bit. So the md1 and md0
are the two partitions that are being mirrored on the two drives. When I
see this...
[2/2] [UU]
That means things are working OK, but when I see this...
[2/1] [U_]
It means that one of the drives has failed.
Thanks!
Mike