The IBM SSA 4-Port RAID Adapter is a new Redundant Array of Independent Disks (RAID) 5 Array adapter in a single initiator per loop environment. It offers RAID 5 function, which provides protection to your data in the unlikely event of a disk drive failure, and non-RAID SSA attachment to the SSA disk drive subsystems. The SSA 4-Port RAID Adapter has Initial Program Load (IPL) capability from non-Raid array disk drives for the 7015 Model R21.