A hot spare pool is a collection of slices (hot spares) reserved by Solaris Volume Manager to be automatically substituted in case of a slice failure in either a submirror or RAID 5 volume. Hot spares provide increased data availability for RAID 1 and RAID 5 volumes. You can create a hot spare pool with either the Enhanced Storage tool within the Solaris Management Console or the command line interface.
When errors occur, Solaris Volume Manager checks the hot spare pool for the first available hot spare whose size is equal to or greater than the size of the slice being replaced. If found, Solaris Volume Manager automatically resynchronizes the data. If a slice of adequate size is not found in the list of hot spares, the submirror or RAID 5 volume is considered to have failed. For more information, see Chapter 15, Hot Spare Pools (Overview).