5.9.9.2. Rebuilding a RAID array

Should /proc/mdstat show that a problem exists with one of the RAID arrays, you can rebuild it by performing the following steps:

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