Chapter 4 Function/System Settings and Display
4.2 Advanced Copy Management
ETERNUS CLI User’s Guide
Copyright 2015 FUJITSU LIMITED
P2X0-1030-09ENZ0
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4.2.5.3
REC Multiplicity
An REC multiplicity value must be set for the REC path between storage systems, and is determined based on
the following two values:
•
Effective line speed (as described in the REC path information file)
•
Round trip time (as actually measured using a CLI command)
The schematic diagram for determining the REC multiplicity is as follows:
4.2.5.4
Assigning REC Buffers
An area that is used to divide REC buffers is called a partition. This area can also be called a group. An REC
buffer must be assigned when the REC Asynchronous Consistency function is used. Up to 8192MB (*1) can be
assigned in the memory space area of REC buffers, and this can be separated into several partitions for each
CM. The maximum number of partitions in the system is 8 (*1). The maximum size of a partition is 2048MB
and the minimum is 128MB. Each partition is handled by specifying its partition number from 0 to 7 (*1).
*1: These are the specification values for the ETERNUS DX440 S2. Values differ among models and types. For details,
refer to the "set rec-buffer" command.
The following example shows how partitions can be assigned for the ETERNUS DX440 S2:
Case.1. No partitions assigned:
Case.2. The maximum size memory is assigned to a single partition:
Case.3. 2048MB of memory is assigned to four separate partitions:
Case.4. 1024MB of memory is assigned to eight separate partitions:
Multiplicity
Output
A different multiplicity
may be manually set.
Recommended value
(Calculated from three values)
Automatic calculation by the system
Effective line speed
(In path information file)
Input (two values)
Round trip time
(Measured value)
8,192MB
2,048MB
2,048MB
2,048MB
2,048MB
2,048MB
1024MB
1024MB
1024MB
1024MB
1024MB
1024MB
1024MB
1024MB
Summary of Contents for Eternus DX410 S2
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