Hitachi Compute Rack CR 210H User Manual page 45

Memory mirroring
Memory mirroring is memory duplication to continue to operate the system unit
without a shutdown in case of an uncorrectable memory error (Uncorrectable
Error: 2-bit error and so on).
These are the following conditions for using the memory mirroring function:
Memory boards should be of the same configuration for channels 0 and 1 as

well as channels 2 and 3 of each processor.
All memory boards should have the same capacity and same model.

When two processors are installed, the same memory configuration should be

applied to processor 1 and processor 2.
Memory mirroring divides memory boards into a primary mirror depending on
channels installed, and configures two channels in pairs. The relationship among
memory slots, channels, and channel pairs is as follows.
Figure 3-17: The memory pair of memory mirroring
System Unit Functions
Hitachi Compute Rack 210H User's Guide
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