IBM 8038, Installation And User Manual

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After you install or remove a DIMM, you must change and save the new
configuration information by using the Setup utility. When you turn on the blade
server, a message indicates that the memory configuration has changed. Start the
Setup utility and select
Save Settings (see “Setup utility menu” on page 50 for
more information) to save changes.
The memory is accessed internally through the system using three channels per
microprocessor. Each channel contains two DIMM connectors. The following table
lists each channel and which DIMM connectors belong to the channel.
Table 2. Memory channel configuration
Memory channel
DIMM connector
(microprocessor 1) DIMM connector
(microprocessor 2)
Channel 1 1 and 2 7 and 8
Channel 2 3 and 4 9 and 10
Channel 3 5 and 6 11 and 12
Depending on the memory mode that is set in the Setup utility, the blade server
can support a minimum of 2 GB and a maximum of 96 GB of system memory on
the system board in a blade server with one microprocessor. If two microprocessors
are installed, the blade server can support a minimum of 4 GB and a maximum of
192 GB of system memory. There are three different memory modes:
v
Independent channel mode: Independent channel mode gives a maximum of 96
GB of usable memory with one microprocessor installed, and 192 GB of usable
memory with two microprocessors installed (using 16 GB DIMMs). The DIMMs
can be installed without matching sizes. See the table below for the memory
installation order.
Table 3. Independent channel mode DIMM installation sequence
One microprocessor installed Two microprocessors installed
DIMM connectors 5, 3, 1, 6, 4, 2 DIMM connectors 5, 11, 3, 9, 1, 7, 6, 12, 4, 10,
2, 8
v
Rank sparing mode: In rank-sparing mode, one memory DIMM rank serves as a
spare of the other ranks on the same channel. The spare rank is held in reserve
and is not used as active memory. The spare rank must have identical or larger
memory capacity than all the other active memory ranks on the same channel.
After an error threshold is surpassed, the contents of that rank is copied to the
spare rank. The failed rank of memory is taken offline, and the spare rank is put
online and used as active memory in place of the failed rank.
Note: Rank sparing mode is supported if the blade server meets one of the
following memory requirements:
– One quad-rank DIMM
– More than one DIMM per channel
– An even number of single-rank or dual-rank DIMMs
For rank sparing mode memory installation order on a blade server with
quad-rank DIMMs, see Table 3.
The following tables show the order that single-rank or dual-rank DIMMs are
installed to use rank sparing mode:
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BladeCenter HS23E Type 8038 and 8039: Installation and User's Guide