Hitachi Universal Storage Platform V Reference Manual page 69

Mode Category
689 TrueCopy Async
and TrueCopy for
z/OS Async
690 Universal
Replicator and
Universal
Replicator for z/OS
Hitachi Universal Storage Platform V/VM User and Reference Guide
This option is used to prevent the initial copy operation when
the Write Pending rate on RCU exceeds 60%.
Mode 689 = ON: The initial copy and resync copy operations
are prevented when the Write Pending rate on RCU exceeds
60%.
Mode 689 = OFF: The initial copy and resync copy operations
are not prevented when the Write Pending rate on RCU
exceeds 60% (the same as before).
Note:
This mode can be set online.
The micro-programs on both MCU and RCU must support
this mode.
This mode should be set per customer's requests.
If the Write Pending status long keeps 60% or more on
RCU, it takes extra time for the initial copy and resync copy
to be completed by making up for the prevented copy
operation.
This option is used to prevent Read JNL or JNL Restore when
the Write Pending rate on RCU exceeds 60% as follows:
When CLPR of JNL-Volume exceeds 60%, Read JNL is
prevented.
When CLPR of Data (secondary)-Volume exceeds 60%, JNL
Restore is prevented.
Mode 690 = ON: Read JNL or JNL Restore is prevented when
the Write Pending rate on RCU exceeds 60%.
Mode 690 = OFF: Read JNL or JNL Restore is not prevented
when the Write Pending rate on RCU exceeds 60% (the same
as before).
Note:
This mode can be set online.
This mode should be set per customer's requests.
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.
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.
Functional and Operational Characteristics
Function Default MCU/RCU
OFF MCU/RCU
OFF RCU
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