IBM #5886 EXP 12S Expansion Drawer for IBM Power Systems

IBM feature #5886 is the EXP 12S Expansion Drawer for IBM Power Systems. It is a two EIA drawer that mounts in a 19-inch rack and holds SAS disk drives or SSDs in twelve hot-swap 3.5-inch SAS bays with redundant data paths to each bay. The drawer has redundant hot-plug power and cooling, two power cords, and redundant hot-swap SAS expanders (service managers), each with its own SCSI Enclosure Services diagnostic processor.

The twelve drives are run by one SAS controller or one pair of controllers, through two SAS attachment ports, from PCIe or PCI-X SAS adapters. The cable depends on the adapter and the protection planned: the large-cache PCI-X adapters #5904 and #5908 use a SAS Y cable for a single port and an X cable for a pair, the medium-cache #5903 is always paired on an X cable, and the zero-cache #5912 and #5901 use a Y cable for one port or an X cable for AIX and Linux pairs.

A second EXP 12S can cascade from the first with two SAS EE cables, which provides 24 bays on the same controller port. The drawer also attaches straight to the SAS port on the rear of the Power 740, 770 and 780. With the #5662 enablement card and the #1819 cable, the embedded controllers run 18 bays, six in the system unit and twelve in the drawer, on a SAS YI cable; every drive in that setup is an HDD and no second drawer cascades. Up to 110 EXP 12S drawers run on SAS PCI controllers in the Power 770 and 780.