About Hot-Spare Drives

A hot-spare is a drive, containing no data, that acts as a standby in the storage array in case a drive fails in a RAID-1, RAID-3, or RAID-5 volume. The hot-spare adds another level of redundancy to the storage array. The Sun StorEdge 6130 array supports up to 15 hot-spares.

If a hot-spare is available when a disk drive fails, the hot-spare is automatically substituted for the failed disk drive, without intervention. The controller uses redundancy data to reconstruct the data from the failed drive onto the hot-spare. When you have physically replaced the failed disk drive, the data from the hot-spare is copied back to the replacement drive. This is called copyback.

If you do not have a hot-spare, you can still replace a failed disk drive while the storage array is operating. If the disk drive is part of a RAID-1, RAID-3, or RAID-5 volume group, the controller uses redundancy data to automatically reconstruct the data onto the replacement disk drive. This is called reconstruction.