IBM 88743BU - System x3950 E, User Manual

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Chapter 3. Hardware configuration
137
Intelligent backup battery unit (iBBU)
The option kit contains the battery package, which is the intelligent battery
backup unit (iBBU). This backup battery must be mounted on the circuit.
An iBBU can charge the battery pack automatically and communicate battery
status information such as voltage, temperature, and current, to the host
computer system.
The backup battery protects cache up to 72 hours, depending on operating
environment. IBM recommends that the battery be replaced annually. A
damaged or no-recoverable battery can be replaced if you submit a service
claim. Table 3-14 lists the replacement part numbers.
Table 3-14 Customer replacement part numbers
Installation guidelines
Consider the following guidelines when using RAID or installing the
ServeRAID-MR10M:
򐂰
The ServeRAID-MR10M can be used in any slot of a x3850 M2 and x3950
M2 complex.
򐂰 The ServeRAID-MR10M is not supported with the ServeRAID manager. Use
the MegaRAID Storage Manager (MSM) instead.
򐂰
One or more arrays can be formed using up to nine cascaded EXP3000. An
x4 SAS SFF8088 cable is required to attach the external storage subsystem
to the ServeRAID-MR10M connectors.
You may have 32 ServeRAID adapters installed in a 4-node multinode complex,
one MR10k and seven MR10M controllers in each node. However, at the time of
Important: The battery in the iBBU must charge for at least six hours under
normal operating conditions. To protect your data, the firmware changes the
Write Policy to
write-through until the battery unit is sufficiently charged. When
the battery unit is charged, the RAID controller firmware changes the Write
Policy to
write-back to take advantage of the performance benefits of data
caching.
Customer replaceable unit (CRU)
part numbers Description
43W4342 iBBU battery package
43W4341 ServeRAID MR10M adapter
43W4343 Carrier