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IBM Power 750 and 760 Technical Overview and Introduction
In addition to the existing SAS disks options, IBM has the following available 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)
There is an expansion option available using 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 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 is 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.
The EXP24S SFF Gen2-bay drawer can be ordered in one of three possible mode settings,
configured by manufacturing (not customer set-up), of 1, 2, or 4 sets of disk bays.
With IBM AIX and Linux, the EXP24S can be ordered with four sets of six bays (mode 4), two
sets of 12 bays (mode 2), or one set of 24 bays (mode 1). With IBM i, the EXP24S can be
ordered as one set of 24 bays (mode 1).
There are six SAS connectors on the rear of the EXP24S drawer to which to SAS adapters or
controllers are attached. They are labeled T1, T2, and T3; there are two T1, two T2, and two
T3 connectors. Figure 2-29 shows the rear connectors of the EXP24S drawer.
In mode 1, two or four of the six ports are used. Two T2 ports are used for a single SAS
adapter, and two T2 and two T3 ports are used with a paired set of two adapters or dual
adapters configuration.
In mode 2 or mode 4, four ports are used, two T2 and two T3, to access all SAS bays.
Figure 2-29 EXP24S SFF Gen2-bay drawer rear connectors
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
cascading
. In this configuration, all 48 SAS bays are controlled
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 750 and Power 760, providing a low-cost disk storage solution.
