1. Installing Internal Optional Devices
Express5800/R120d-2M User’s Guide
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Chapter 2 Preparations
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Memory Sparing Feature
Memory Sparing feature puts a memory channel 2 of a memory controller in each CPU into standby status as
spare devices. If a correctable error occurs in a DIMM in the running memory controller, the feature
automatically changes the running DIMM from the failed one to a DIMM in the standby state to continue the
processing.
Note
To use Memory Sparing feature, install N8102-476/477/499/500 additional memory board
(three DIMMs of same model).
Tips
The operating system recognizes the DIMMs as those with capacities less than the actual
physical capacities. (The recognized capacities vary depending on the number of DIMMs
and the physical capacity per DIMM.)
The following table shows configuration allowable for memory sparing and system logical memory capacity.
Number of
CPUs
Number of
DIMMs
Capacity of DIMM installed
2GB
4GB
8GB
16GB
1
3
4GB
8GB
20GB
40GB
6
8GB
16GB
40GB
80GB
9
12GB
24GB
60GB
120GB
12
16GB
32GB
80GB
160GB
2
6
8GB
16GB
40GB
80GB
12
16GB
32GB
80GB
160GB
18
24GB
48GB
120GB
240GB
24
32GB
64GB
160GB
320GB