Memory Sparing - IBM 7378 Problem Determination And Service Manual

The following illustration shows the memory connector layout that is associated with
each microprocessor. For example, DIMM connectors 9, 10, 11, 12, 13, 14, 15, and
16 (DIMM connectors are shown underneath the boxes) are associated with
microprocessor 2 socket (CPU2), and DIMM connectors 1, 2, 3, 4, 5, 6, 7, and 8
are associated with microprocessor 1 socket (CPU1). The numbers within the boxes
indicate the installation sequence of the DIMM pairs. For example, the first DIMM
pair (indicated within the boxes by 1s) should be installed in DIMM connectors 3
and 6, which are associated with microprocessor 1 (CPU1).
Note: You can install DIMMs for microprocessor 2 as soon as you install
microprocessor 2; you do not have to wait until all of the DIMM connectors for
microprocessor 1 are filled.
The following table lists the installation sequence for installing DIMMs in
memory-mirroring mode.
Table 13. DIMM installation sequence for memory-mirroring mode
DIMMs
First pair of DIMMs
Second pair of DIMMs
Third pair of DIMMs
Fourth pair of DIMMs
Fifth pair of DIMMs
Sixth pair of DIMMs
Note: DIMM connectors 7, 8, 15, and 16 are not used in memory-mirroring mode.
When you install or remove DIMMs, the server configuration information changes.
When you restart the server, the system displays a message that indicates that the
memory configuration has changed.

Memory sparing

The server supports memory sparing. This feature disables the failed memory from
the system configuration and activates a DIMM to replace the failed active DIMM.
You can enable either memory sparing or memory mirroring in the Setup utility (see
"Using the Setup utility" on page 303). When you use the memory sparing feature,
consider the following information:
v The memory sparing feature is supported on server models with an Intel Xeon
5600 series microprocessor.
v When you enable the memory sparing feature, you must install three DIMMs per
microprocessor at a time. The first DIMM must be in channel 0, the second
DIMM in channel 1, and the spare DIMM in channel 2. The DIMMs must be
Number of installed
microprocessors
1
1
1
2
2
2
Chapter 5. Removing and replacing server components
DIMM connector
3, 6
2, 5
1, 4
14, 11
13, 10
12, 9
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