How Hot Spares Work

When a slice in a submirror or RAID 5 volume fails, a slice from the associated hot spare pool is used to replace it. Solaris Volume Manager searches the hot spare pool for a hot spare based on the order in which hot spares were added to the hot spare pool. The first hot spare found that is large enough is used as a replacement. The order of hot spares in the hot spare pools is not changed when a replacement occurs.

When you add hot spares to a hot spare pool, add them from smallest to largest. This strategy avoids potentially wasting “large” hot spares as replacements for small slices.

When the slice experiences an I/O error, the failed slice is placed in the “Broken” state. To fix this condition, first repair or replace the failed slice. Then, bring the slice back to the “Available” state by using the Enhanced Storage tool within the Solaris Management Console or the metahs -e command.

When a submirror or RAID 5 volume is using a hot spare in place of an failed slice and that failed slice is enabled or replaced, the hot spare is then marked “Available” in the hot spare pool, and is again ready for use.