Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

6-22 Performing TrueCopy for z/OS Pair Operations
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
Note: If there is no period of time without recordsets (i.e., recordsets
continue to be generated), the RCU will discontinue the original
Suspend Pair operation and forcibly suspend the pair.
Purge: The MCU will change the pair status from Suspending to
Suspend as soon as the RCU accepts the suspend pair operation. The
MCU and RCU discard all pending recordsets and mark the
cylinders/tracks that contain discarded recordsets as modified in the M-
VOL and R-VOL bitmaps, respectively. When the pair is resynchronized,
the M-VOL and R-VOL bitmaps will be merged at the MCU, and all
cylinders/tracks marked as modified will be copied to the R-VOL.
Note: If the MCU does not receive acknowledgement of the suspend
operation from the RCU within the copy pending timeout setting, the
MCU will forcibly suspend all affected TCz Async pairs and report an
IEA491E host console message.
WARNING: The QUIESCE option of the CSUSPEND command has been
disabled by APAR OW15247 or APAR OW15248. Refer to either of these APARs
and the latest IBM PPRC documentation for detailed information on the
QUIESCE option of the CSUSPEND command. Please check with your Hitachi
account team before using the CSUSPEND command with the QUIESCE option
to suspend TCz pairs on USP V storage systems. If the CSUSPEND command
with the QUIESCE option is issued to certain volumes (e.g., active SPOOL,
PAGE, or CATALOG datasets, active SYSRES volume), the attached host(s)
may enter a deadlock condition and may require a storage control IML to
correct the condition. TCzA does not support the CSUSPEND/QUIESCE option.
Note: If you select a pair from the volume list and change the settings, and if
you use a drop-down list to set blank to a parameter, the parameter takes the
default value for each pair. If you select the settings from the preview list
before applying the changed settings, and if you use a drop-down list to set
blank to a parameter in the Suspend Pair dialog box, the parameter value in
the preview list will not be changed.
To suspend one or more TrueCopy for z/OS pairs:
1. If you plan to suspend one or more TCzA pairs using the drain suspend
option, you must STOP all application I/Os to the TCzA M-VOL(s) before
suspending the pair(s). This ensures that all pending data in cache is written
to the R-VOL(s) during pair suspension. You do not need to vary the M-
VOL(s) offline.
2. Connect to the MCU or RCU of the pair(s) to be suspended, open the
TrueCopy for z/OS Pair Operation window. For TCz Synchronous, you must
connect to the MCU. For TCzA, you can connect to the MCU or RCU.
3. In the tree, select the CU or the upper CU grouping, which contains the
pair(s) to be suspended.