IBM Power ESE 8412-EAD, Manual

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– Background data scrubbing
– Disks formatted to 528 bytes per sector, providing cyclical redundancy checking (CRC) and
logically bad block checking
– Optimized hardware for RAID 5 and 6 sequential write workloads
– Optimized skip read/write disk support for transaction workloads
175 MB cache RAID – Dual IOA enablement card
This feature is used to enable write cache on the two embedded SAS RAID adapters of the disk
or media backplane by providing the necessary rechargeable batteries for memory backup. It also
enables the two embedded SAS RAID adapters to work as dual storage IOAs, that is, high
availability (HA) RAID mode. This feature plugs in to the disk or media backplane and enables a
175 MB write cache on each of the two embedded RAID adapters by providing two rechargeable
batteries with associated charger circuitry. The write cache can provide additional I/O
performance for attached disk or solid-state drives, particularly for RAID 5 and RAID 6. The
write cache contents are mirrored for redundancy between the two RAID adapters resulting in an
effective write cache size of 175 MB. The batteries provide power to maintain both copies of
write-cache information in the event power is lost.
Related information :
Serial-attached SCSI cable planning
SAS storage configurations
Several SAS subsystem configurations are supported on the 8412-EAD, 9117-MMB, 9117-MMC,
9117-MMD, 9179-MHB, 9179-MHC, or 9179-MHD systems.
The configuration you use depends on the combination of SAS features that you have installed on your
system. The following table provides an overview of the features and related configurations.
Table 2. SAS subsystem configurations
SAS
subsystem
configuration
175 MB Cache
RAID - Dual
IOA
enablement
card (FC 5662)
External SAS
components
SAS port cables SAS cables Limitations
Two-way split
backplane No
Note:
The two
embedded SAS
adapters report
as CCIN 57C7.
None None Not applicable
v
IBM i is not
supported.
v
Connecting to an
external disk
enclosure is not
supported.
v
Each set of three
drives can be
HDDs or SSDs.
Three-way
split
backplane No
Note: The two
embedded SAS
adapters report
as CCIN 57C7.
Dual-x4 SAS
adapter (FC 5901:
CCIN 57B3) Internal SAS port
(FC 1815): SAS
cable for
three-way split
backplane AI cable (FC 3679):
Adapter to internal
drive 1 meter
v IBM i is not
supported.
v
An I/O adapter
can be located in
another enclosure
of the system.
v
Each set of two
drives can be
HDDs or SSDs.
4
SAS subsystem