Provides a disk controller with auxiliary write cache to improve cache data redundancy. The #5581 includes a #2757 PCI-X Ultra4 RAID Disk Controller and a secondary IOA with 757MB of auxiliary maximum compressed write cache. The #2757 and the secondary IOA each require one PCI-X slot and must be installed together in the same CEC or I/O unit/drawer/tower. The #2757 and the auxiliary write cache IOA are connected by a SCSI cable (provided). Feature #2757 will not appear on IBM ordering, shipping, or inventory documentation.

The connecting SCSI cable is attached to port four of the #2757, reducing the number of SCSI buses that support disk drives from four to three. The reduction of SCSI buses may also reduce the number of disk drives supported by the #2757, depending on the CEC or I/O unit/ drawer/tower in which the #2757 is installed. No disk drives are driven by the auxiliary write cache IOA.

Attributes provided: Disk Controller with auxiliary write cache

Attributes required: Two PCI-X slots within the same CEC or I/Ounit/drawer/tower

For 8203-E4A: The IBM Power6 8203-E4A (#5581)

Minimum required: 0

Maximum allowed: 36 (Initial order maximum: 0)

OS level required: IBM i V5R4 with V5R4M5 Machine Code, or later.

Initial Order/MES/Both/Supported: Supported

CSU: Yes

Return parts MES: Does not apply

Note: Not supported in CEC. System maximum of 24 under IBM i. Not supported under AIX or Linux.