HP StorageWorks XP Remote Web Console Software - Manual (Page 128)

128 Hitachi TrueCopy z/OS for HP XP12000/XP10000 and SVS 200 storage systems
The 15 Tracks setting speeds up the initial copy operation, but may affect the disk array’s I/O
performance if the M-VOL is experiencing high write I/O activity. This setting is functionally
equivalent to the PACE=2-255 parameter for the CESTPAIR TSO command.
The 3 Tracks setting slows down the initial copy operation to minimize the impact of the initial copy
operation on the disk array’s I/O performance. This setting is functionally equivalent to the PACE=1
parameter for the CESTPAIR command.
• Priority (From 1 to 256): The initial copy priority specifies the order in which the initial copy
operations will be performed if the number of requested initial copy operations is greater than the
maximum initial copy activity setting on the RCU Option window (see ” Registering an RCU (Add
RCU) ” on page 87). The highest priority is 1 and the lowest priority is 256 (current default = 32).
The TC390 initial copy priority option can be used to spread initial copy operations across disk
array groups and/or disk array domains (ACP pairs) to reduce initial copy time as well as host I/O
contention.
Example: The maximum initial copy activity setting is 4 and you add 6 TC390 pairs at the same
time (for LDEVs 00 through 05) with the initial copy priority set as follows:
The MCU will start the initial copy operations for LDEVs 03, 05, 00, and 04 immediately, then start
LDEV 01 when one of the first four initial copy operations is complete, and then start LDEV 02 when
the next initial copy operation is complete. If additional TC390 pairs are added, the MCU also
prioritizes the initial copy operations by time requested so that all TC390 pairs in the first group are
started before any pair in the next group is started.
NOTE: The CESTPAIR TSO command does not support the initial copy priority option. When
CESTPAIR is used to establish TC390 pairs, the initial copy operations are performed in the order
that the CESTPAIR commands are issued.
NOTE: If the time out error occurs during the Add Pair operation, the copy operation may not be
executed correctly in the order that you have set with the Priority parameter. The time out error may
be caused by the CU configuration or a remote copy path error. Review the error, delete the pair
with the error, and then retry the Add Pair operation.
• Difference Management. Specifies the measurement method that TrueCopy for system 390 will use
to manage the differential data for the pair: auto, cylinder, or track. The default setting is Auto.
When you select Auto, either Cylinder or Track is selected depending on the basic size of the
logical volume image. See ” Difference management ” on page 27 for further information on this
option.
• The CFW Data option specifies whether the CFW data will be copied to the R-VOL:
If Copy to R-VOL is selected, the MCU will copy the CFW data to the R-VOL.
If Only M-VOL is selected, the MCU will not copy the CFW data to the R-VOL. This setting is
recommended for two reasons: (1) copying the CFW data impacts disk array performance and (2)
CFW data is typically used for temporary files (for example, sort work datasets) that are not usually
required for disaster recovery.
M-VOL of TC390 pair Priority
LDEV 03 1
LDEV 05 2
LDEV 00 3
LDEV 04 4
LDEVs 01, 02 5