Figure19 shows how RAID-5 arrays can be protected against the complete failure of an
SSAenclosure. Each pdisk of each array (hdisk) is in a different SSA enclosure. The
hot spare disk drives are also in a different enclosure. PoolsA1 and A2 each contain an
hdisk and a hot spare disk drive. The pools ensure that, if any one SSAenclosure fails
completely,three disk drives are always available for each hdisk.
Pool A2
hdisk hdisk
Pool A1
Enclosure-1
Enclosure-2
Enclosure-3
Enclosure-4
pdisk
pdisk
pdisk
Spare Spare
pdisk
pdisk
pdisk
Figure19. Pools and Hdisks across Enclosures
Chapter5. Hot Spare Management 49