Replacing a failed drive in a Software RAID mirror set

Like I wrote about last time, I have a failing drive in my triple active RAID mirror set on my firewall box. See also "Failing hard drive in a Software RAID". I'm still trying to decide whether the disk has actually failed, or if it is just having issues.

# /sbin/badblocks -sv /dev/sdc2

Since I have unmounted this RAID slice, I'm going to test with a DESTRUCTIVE write/read verification. (Which is also a good way to wipe the disk.)

# /sbin/badblocks -sv -w -t random /dev/sdc2

Well, after a few runs with that, the disk is no longer making "retry" noises. So I'm going to re-add the slice to the RAID array and see what happens.

# /sbin/mdadm /dev/md1 -a /dev/sdc2

And force mdadm to verify the sync:

# echo check > /sys/block/md1/md/sync_action

It seems to be working. I'm guessing that I finally convinced SMART to re-map the bad sector that was causing problems.