NEC express5800 A2010b User Manual page 200

Chapter 2 Preparations
Occurrence of Rank Sparing error (When the different DIMMs are used for failing rank and spare rank)
Memory Riser #1
LockStep
PAIR#1-1
PAIR#1-2
PAIR#1-3
PAIR#1-4
Transfer to
running system
LockStep
PAIR#3-1
PAIR#3-2
Isolate
PAIR#3-3
PAIR#3-4
occurrence
This feature can be used under the following conditions:
•
Both DIMMs in Lock Step Pair (DIMM#1/2, DIMM#3/4, DIMM#5/6, DIMM#7/8) must be of same model.
•
Each memory channel must have two or more DIMMs or 3Rank or higher rank.
(6)
LockStep + Mirroring
In LockStep + Mirroring mode, mirroring memory is added to Lock Step mode, and regularly copies the contents
of memory onto mirroring memory. If the memory error is detected, the mirroring memory takes over to continue
processing.
Mirroring is performed between SMI channels in memory controller, as shown in the figure below. In principle,
the SMI channel having younger number (SMI0) is defined as duplication origin.
RAS feature is higher than LockStep mode and LockStep + Rank Sparing mode, however, the memory capacity
available for OS is reduced to half of installed memory capacity.
200
DIMM #1
DIMM #2
RANK0 RANK0
RANK1 RANK1
RANK2
RANK2
RANK3 RANK3
DIMM #5
DIMM #6
RANK0 RANK0
RANK1 RANK1
RANK2 RANK2
RANK3 RANK3
CH0 CH1
Failure
Memory Buffer #1
SMI0
Memory Controller #1
•
Note Combinations of channels 0 and 1, and 2 and 3 are used in .Lock Step + Mirroring
mode.
•
Use NE3302-H030F/H031F/H032F/H033F additional memory for Step + Mirroring
mode.
•
Use the DIMMs of same model for Lock Step PAIR and Mirroring PAIR.
Express5800/A1040b, A2040b, A2020b, A2010b User's Guide
1. Installing / Removing Internal Options
DIMM #3 DIMM #4
LockStep
PAIR#2-1 RANK0 RANK0
PAIR#2-2 RANK1
RANK1
PAIR#2-3
RANK2 RANK2
PAIR#2-4
RANK3 RANK3
DIMM #7
DIMM #8
LockStep
PAIR#4-1
RANK0 RANK0
PAIR#4-2
RANK1 RANK1
PAIR#4-3
RANK2 RANK2
PAIR#4-4
RANK3 RANK3
CH2 CH3
Memory Buffer #2
SMI1
Processor
Running
system
Standby
(spare rank)
SMI2 SMI3
Memory Controller #2