Understanding Hot Spares
A hot spare is an unused backup physical disk that can be used to rebuild data from a redundant virtual disk. Hot spares remain in standby mode. When a physical disk that is used in a redundant virtual disk fails, the assigned hot spare is activated to replace the failed physical disk without interrupting the system or requiring your intervention. If a virtual disk using the failed physical disk is not redundant, then the data is permanently lost without any method (unless you have a backup) to restore the data.
Hot spare implementation varies for each controller controller. For more information on hot spares, see:
The following sections describe procedures for assigning a hot spare: