A hot spare is a drive containing no data that acts as a standby in case a drive fails in a RAID 1, 3, or 5 Logical Drive. The hot spare drive adds another level of redundancy to your Storage Subsystem. If a drive fails, the hot spare takes over for the failed drive until you replace it.
A hot spare drive is not dedicated to a specific array but instead is global (can be used for any failed drive in the Storage Subsystem with the same or smaller capacity).
A Hot Spare Drive - Standby, represented by this icon in the Subsystem Management Window Physical View , is a drive that has
been assigned as a hot spare but is currently not taking over for any failed drive.
A Hot Spare Drive - In Use, represented by this icon in the Subsystem Management Window Physical View , is a drive that has
been assigned as a hot spare and is currently taking over for a failed drive.