RAID Disk Failure Protection

All RAID types except for RAID 0 can tolerate a specific number of disk failures without losing data. When a disk in a RAID group fails, the RAID group status changes to degraded and then QTS performs one of the following actions.

Spare Disk Available	Actions
Yes	QTS automatically replaces the failed disk with a spare disk and then starts rebuilding the RAID group. The status of the RAID group changes to `rebuilding`, and then changes back to `Ready` after rebuilding has finished.
No	You must replace the failed disk manually. QTS starts rebuilding the RAID group after you have installed a working disk.