Mode
Category
Description
Default
MCU/RCU
474
Universal
Replicator
UR initial copy performance can be improved by
issuing a command from CCIto execute a dedicated
script consisting of UR initial copy (Nocopy), UR
suspend, TC Sync initial copy, TC Sync delete, and UR
resync.
Mode 474 = ON:
For a suspended UR pair, a TC
(Sync) pair can be created with the same P-VOL/S-
VOL so that UR initial copy time can be reduced by
using the dedicated script.
Mode 474 = OFF (default):
For a suspended UR pair,
a TC (Sync) pair cannot be created with the same P-
VOL/S-VOL. For this, the dedicated script cannot be
used.
If the P-VOL and S-VOL are both DP-VOLs, initial copy
performance might not improve with SOM 474 set to
ON. This is because with DP-VOLs, not all areas in a
volume are allocated for UR; therefore not all areas
in the P-VOL are copied to the S-VOL. With less than
the full amount of data in the P-VOL being copied,
the initial copy completes in a shorter time, which
might not be improved with SOM 474.
Notes:
1.
Set this SOM for both primary and secondary
storage systems.
2.
When this SOM is set to ON:
■
Execute all pair operations from CCI/BCM.
■
Use a dedicated script.
■
Initial copy operation is prioritized over
update I/O. Therefore, the processing speed
of the update I/O slows down.
3.
If this SOM is set to ON, the processing speed of
update I/O slows down by about 15 μs per
command, version downgrade is disabled, and
Take Over is not available.
4.
If this SOM is not set to ON for both sides, the
behavior is as follows:
■
OFF in primary and secondary storage
systems: Normal UR initial copy
performance.
■
ON in the primary storage system/OFF in the
secondary storage system: TC Sync pair
creation fails.
OFF
Both
System option modes
Appendix B: System option modes
System Administrator Guide for VSP Gx00 models and VSP Fx00 models
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Summary of Contents for Virtual Storage Platform F400
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