Disk drives in a storage system are spun up in sequential stages. During
each sequential stage a number of disk drives is spun up based on
parameters related to the power requirements of the system. The
parameters include the maximum current for the storage system, the number
of disk drives currently in steady state, the steady state current
required for a disk drive, and the spin up current required for a disk
drive. High availability features are provided as further aspects of the
spin up mechanism.