HP XP P9500 Storage - Manual (Page 32)

Table 2 System option modes (continued)
Description Mode
•
Delete the Cnt Ac-S pair.
•
Resynchronize the Cnt Ac-J pair.
Mode 474 ON: Using RAID Manager improves performance.
Mode 474 OFF: Operations run normally.
If the P-VOL and S-VOL are both THP V-VOLs, initial copy performance might not improve
with SOM 474 set to ON. This is because with THP V-VOLs, not all areas in a volume
are allocated for Cnt Ac-J; 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 may not be improved with SOM 474.
Notes:
1. Set this mode for both MCU and RCU.
2. When this mode is set to ON:
-Execute all pair operations from RAID Manager/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.
-Version downgrade is disabled.
-Take Over is not available.
3. If this mode is not set to ON for both sides, the behavior is as follows:
-With setting on MCU/without setting on RCU: Cnt Ac-S 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.
4. This mode cannot be applied to a Cnt Ac-J pair that is the second mirror in a Cnt
Ac-JxCnt Ac-J multi-target configuration, Cnt Ac-JxCnt Ac-J cascade configuration, or
3DC multi-target or cascading configuration of three Cnt Ac-J sites. If applied, Cnt
Ac-S pair creation is rejected with SSB=CBED output.
Enables the delta resync operation. 506
Mode 506 ON: The delta resync operation is performed if there are no update I/Os.
Mode 506 OFF: The copy processing of all data is performed if there is no update
I/Os.
Controls whether to prevent Read JNL or JNL Restore when the Write Pending rate on
RCU exceeds 60% as follows: 690
• When CLPR of JNL-Volume exceeds 60%, Read JNL is prevented.
•
When CLPR of Data (secondary)-Volume exceeds 60%, JNL Restore is prevented.
MCU/RCU: This SOM applies to only the RCU.
Mode 690 ON: Read JNL or JNL Restore is prevented when the Write Pending rate on
RCU exceeds 60%.
Mode 690 OFF (default): Read JNL or JNL Restore is not prevented when the Write
Pending rate on RCU exceeds 60% (the same as before).
Notes:
1. This SOM can be set online.
2. If the Write Pending status long keeps 60% or more on RCU, it takes extra time for
the initial copy to be completed by making up for the prevented copy operation.
3. If the Write Pending status long keeps 60% or more on RCU, the pair status may
become Suspend due to the JNL-VOL being full.
4. When XP12000 Disk Array/XP10000 Disk Array is used on P-VOL side, this SOM
cannot be used. If this SOM is set to ON, SSB=8E08 on P- VOL side and SSB=C8D1
on S-VOL side may frequently be output.
Changes cache memory (CM) capacity allocated to MPBs with different workloads. 908
32 Planning volumes, P9500 systems