Determining Which Physical Drive Matches Which Logical Device

[Curtis Doty]

vamythguy wrote:
> I have a RAID-5 array with four SATA disks in it.  Apparently, two are
> going
> bad, so I want to replace them.  But, I'm not sure which physical
> drives to
> pull.  Given the following:
>
> cat /proc/mdstat
> Personalities : [raid6] [raid5] [raid4]
> md0 : active raid5 sda[0] sdd[3] sdc[2] sdb[1]
>      735351936 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
>
> Any suggestions?

Odd that you have the raid4 and raid6 modules loaded, but still
unfamiliar with /proc/mdstat...

Anyways, you are showing an array with four working disks; none failed.
If you had a failed drive, it might look like [U_UU] which would mean
the second disk had failed.

../C