Hitachi Compute Rack CR 210H User Manual page 44

In the case of a memory board having one rank, one memory board becomes
spare memory.
The online spare memory function becomes valid again when you restart the
system unit. At this time, the spare memory is set again. Therefore, replace the
failed memory board before restarting the system unit.
The precautions on the use of online spare memory are as follows:
The spare memory is set to every channel of each processor.

To validate the online spare memory function, set Chipset > North Bridge

> Memory Mode to Sparing on the system BIOS setup menu.
The online spare memory functions in the channel of each processor once.

The online spare memory function does not work then to become invalid even
if a memory fault occurs with other channels of the processor.
When the online spare memory function is set valid, one rank of a memory

board to be installed on each channel is used as a spare memory. Therefore,
the memory capacity is displayed smaller than the actual one.
On the system BIOS setup menu, confirm Chipset > North Bridge > Total
Memory.
Depending on a memory board installed, the spare memory capacity per
channel is as follows:
Table 3-2: Spare memory capacity
Installed memory boards
MJ702GL3-Y /
MJ702GL3-R
MJ704GL3-Y /
MJ704GL3-R
MJ708GL3-Y /
MJ708GL3-R
MJ716GL3-Y /
MJ716GL3-R
If memory degradation occurs, the online spare memory function becomes

invalid.
The OS might operate slowly within a range of a few seconds to ten minutes while

the online spare memory function is working to change over to spare memory.
In case of an uncorrectable memory error (Memory Uncorrectable Error: 2-bit

error and so on), the online spare memory function does not work.
When the online spare memory function works to change over to spare

memory, the MAINTENANCE LED 2 in front of the system unit is turned on.
See MAINTENANCE LEDs
You cannot use the online spare memory function simultaneously with

memory mirroring, lock step, and device tagging.
3-22
Spare memory capacity per channel
2048 MB
4096 MB
4096 MB
8192 MB
on page 2-3
System Unit Functions
Hitachi Compute Rack 210H User's Guide