Specifies the disk to be designated as the Spare disk(s).
            Multiple disks must be enclosed in parenthesis. Assigning a
            spare disk to an unit in a drive group will assign the
            spare disk to all the configured units in the drive group.

            If an unit is created on a disk group to which a spare disk
            is assigned, then the spare disk will be configured to the
            new unit (if it is not a RAID 0 unit). One spare disk can be
            assigned to multiple drive groups.

            Ensure that the size of the spare disk is at least equal to
            the size of the smallest drive in the drive group.

            Format:
                    /SPARE=(disk_number[,...])

            Note: The disk numbers for the existing disks can be obtained
                  using the SHOW DISKS command.