5.9.9.2. Rebuilding a RAID array

Remove the disk from the raid array.

mdadm --manage /dev/md0 -r /dev/sdc3

Remove the disk from the system.

Using fdisk, replace the removed disk and re-format the replacement disk.

Add the new disk back to the RAID array.

mdadm --manage /dev/md0 -a /dev/sdc3

To restore the disk, perform a "software fail" the previous spare slice:

mdadm --manage --set-faulty /dev/md0 /dev/sdc3

The system will now attempt to rebuild the array on the replaced disk. Use the following command to monitor status:

watch -n 1 cat /proc/mdstat

When the array is finished rebuilding, remove and then re-add the software-failed disk back to the array.

mdadm --manage /dev/md0 -r /dev/sdc3

mdadm --manage /dev/md0 -a /dev/sdc3

Check the array.

mdadm --detail /dev/md0