Recovering a RAID 10 single-disk failure
When a single disk in a RAID 10 disk array fails, the disk array status changes to Degraded. The disk array remains functional because the data on the Failed disk is also stored on the other member of its mirrored pair.
When ever a disk fails, replace it as soon as possible.
If a hot spare disk is available, the controller can rebuild the data
on the disk automatically. If a hot spare disk is not available, you
will need to replace the failed disk and then initiate a rebuild.
Complete the following steps to initiate a rebuild: