User guide

B–8 System option modes
Hitachi Unified Storage VM Block Module Hardware User Guide
474 Universal
Replicator
UR initial copy performance can be improved by issuing
a command from CCI/BC Manager to execute a dedicated
script consists 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.
Note:
1. Set this mode for both MCU and RCU.
2. When the mode is set to ON;
- Execute all of 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 by about 15?s per command.
3. If this mode is set to ON, the processing speed of
update I/O slows down by about 15?s per command,
version downgrade is disabled, and Take Over is not
available.
4. If the mode is not set to ON for both or either sides,
the behavior is as follows.
- Without setting on both sides: Normal UR initial copy
performance.
- With setting on MCU/without setting on RCU: TC Sync
pair creation fails.
- Without setting on MCU/with setting on RCU: The
update data for P-VOL is copied to the S-VOL in
synchronous manner.
- While the mode is set to ON, micro-program downgrade
is disabled.
- While the mode is set to ON, Take Over function is
disabled.
- The mode cannot be applied to a UR pair that is the 2nd
mirror in URxUR multi-target configuration or URxUR
cascade configuration. If applied, TC pair creation is
rejected with SSB=CBEE output.
OFF MCU/
RCU
Mode Category Description Default
MCU/
RCU