Memory Mirror - Fujitsu PRIMEQUEST 2000 Series Design Manual

2.2.2 Memory (7/7)

Memory Mirror

n
• Mirroring is performed between the memory group in MB#xA and MB#xB and the memory
group in MB#xC and MB#xD that are controlled by the same CPU.
• Memory Mirror is available even if only one CPU is installed in an SB.
Memory Spare
n
• When multiple DIMM pairs are configured, a DIMM rank is used as a spare of other ranks.
• If the number of correctable errors that occur in a specific time period in a rank exceeds a
threshold, the contents of the memory are copied to the rank that has been reserved as a
spare and the DIMM rank in which the errors occurred is disconnected.
* Memory Mirror and Memory Spare cannot be enabled together.
Mirroring is available only between the same types of memory.
Intra-CPU
mirroring
PRIMEQUEST 2000 Series Design Guide
Memory Mirror
DIMM pair
Rank 0 Rank 0
Single rank
DIMM A DIMM B
* The available memory capacity is two-thirds of the total capacity of the installed memory.
DIMM pair
Rank 0 Rank 0
Dual rank
Rank 1 Rank 1
DIMM A DIMM B
* The available memory capacity is five-sixths of the total capacity of the installed memory.
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Memory Spare
DIMM pair DIMM pair
Rank 0 Rank 0 Rank 0 Rank 0
DIMM C DIMM D DIMM E DIMM F
DIMM pair DIMM pair
Rank 0 Rank 0 Rank 0 Rank 0
Rank 1 Rank 1 Rank 1 Rank 1
DIMM C DIMM D DIMM E DIMM F
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Spare
Spare