IBM Power 780 Technical Overview And Introduction page 112

SFF-2 SAS drives that physically do not fit in the Gen1 or SFF-1 bays of the POWER7 or
POWER7+ system unit or of the 12X PCIe I/O Drawers, or vice versa.
The EXP24S SAS ports are attached to a PCIe SAS adapter or pair of adapters. The
EXP24S can also be attached to an embedded SAS controller in a server with an embedded
SAS port or to the integrated SAS controllers in the EXP30 Ultra SSD I/O Drawer. The SAS
controller and the EXP24S SAS ports are attached by using the appropriate SAS Y or X or
EX cables.
The following internal SAS adapters support the EXP24S:
PCIe 380 MB Cache Dual - x4 3 Gb SAS RAID Adapter (FC 5805 CCIN 574E)
PCIe dual port x4 SAS adapter (FC 5901 CCIN 57B3)
PCIe 380 MB Cache Dual - x4 3 Gb SAS RAID adapter (FC 5903 CCIN 574E)
PCI-X DDR 1.5 GB Cache SAS RAID Adapter (BSC; FC 5908)
PCIe2 1.8 GB Cache RAID SAS adapter Tri-port 6 Gb (FC 5913 CCIN 57B5)
PCIe2 RAID SAS adapter Dual-port 6 Gb (FC ESA1 CCIN 57B4)
The SAS disk drives that are contained in the EXP24S SFF Gen2-bay Drawer are controlled
by one or two PCIe SAS adapters that are connected to the EXP24S through SAS cables.
The SAS cable varies, depending on the adapter being used, the operating system being
used, and the protection that is needed.
In addition to the existing SAS disks options, IBM offers the following disk models:
900 GB 10K RPM SAS HDD in Gen-2 Carrier for AIX and Linux (FC 1752)
856 GB 10K RPM SAS HDD in Gen-2 Carrier for IBM i (FC 1738)
Considerations:
The medium cache PCIe 380 MB Dual - x4 3 Gb SAS RAID Adapter (FC 5903) is
always paired and uses a SAS X cable to attach the FC 5887 I/O drawer.
The PCIe Gen2 1.8 GB Cache RAID SAS Adapter (FC 5913) uses SAS YO cables.
In all of these configurations, all 24 SAS bays are controlled by a single controller or a
single pair of controllers.
A second EXP24S drawer can be attached to another drawer by using two SAS EE
cables, providing 48 SAS bays instead of 24 bays for the same SAS controller port. This
configuration is called
by a single controller or a single pair of controllers.
The EXP24S drawer can be directly attached to the SAS port on the rear of the
Power 770 and Power 780, providing a low-cost disk storage solution.
An expansion option is available that uses the paired embedded controller configuration with
the 175 MB Cache RAID - Dual IOA Enablement Card (FC 5662 CCIN 2B2) and the SAS
expansion port. The SAS expansion port can add more SAS bays to the six bays in the
system unit. A EXP24S disk drawer in mode 1 can be attached by using a SAS port on the
rear of the processor drawer, and its 24 SAS bays are run by the pair of embedded
controllers.
The pair of embedded controllers are now running 30 SAS bays (six SFF bays in the system
unit and 24 SFF bays in the drawer). The disk drawer is attached to the SAS port with an SAS
YI cable and the embedded controllers connected to the port using the SAS cable assembly
(FC 1819). In this 30-bay configuration, all drives must be HDDs.
A second unit cannot be cascaded to an EXP24S SFF Gen2-bay drawer attached in this way.
98
IBM Power 770 and 780 (9117-MMD, 9179-MHD) Technical Overview and Introduction
cascading
. In this configuration, all 48 SAS bays are controlled