Besides building fabric resiliency, the data in the storage arrays must be protected
against disk failures using several mechanisms. The volumes in the
storage units must be configured as mirrored or RAID-5 volumes. Certain
disks must be designated as hot spares to automatically replace a failed disk in
a mirrored or RAID-5 volume. The disks must be hot-swappable to allow you
to replace failed disks without having to off-line the storage array.