Hitachi TrueCopy for z/OS (T1711-96009, June 2006)

TrueCopy for z/OS user guide 131
NOTE: With the setting of Volume for Resume Range, if there are Duplex status pairs and pairs
other than Duplex status in the same consistency group, unexpected suspend may occur during the
pair operations (Suspend, Delete, and Resume) under the heavy I/O load conditions. You can
estimate whether the I/O load condition is heavy or not from the rate of sidefile cache (around
30%), or from the frequency of the host I/O if you cannot see the rate of sidefile cache. The pair
operations should be performed under the light I/O load condition.
For more information about the option parameters, see ”Creating TrueCopy Volume Pairs (Add Pair)”
on page 121.
NOTE: The CESTPAIR (MODE=RESYNC) command can be used to resume suspended TC390
Synchronous and TC390A pairs (see ”Using PPRC Commands for TrueCopy” on page 153).
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 preset list before applying the changed settings, and if you use a drop-down list to set blank to a
parameter in the Resume Pair panel, the parameter value in the preset list will not be changed.
NOTE: If an MCU/RCU is powered off and its backup batteries are fully discharged while TC390 pairs
are suspended, the M-VOL/R-VOL cylinder bitmaps will not be retained. In this unlikely case, the
MCU/RCU will mark all cylinders of all split or suspended TC390 volumes as modified so that the MCU
will perform the equivalent of an entire initial copy operation when the pairs are resumed.
To resume one or more split or suspended TC390 volume pairs:
1. If any pair was suspended due to an error condition (use the Pair Status window to view the suspend
type), verify that the error condition has been removed (see ”General TrueCopy Troubleshooting” on
page 147 for troubleshooting instructions). The MCU will not resume the pair(s) until the error condition
has been removed.
2. Connect to the MCU of the pair(s) to be resumed and start the TC390 software.
3. From the CU Number tree on the TrueCopy main window, select the number of the correct CU image.
4. If you are resuming split or suspended Volumes, select the pair(s) on the Volume list on the TrueCopy
main window. Select Suspended pairs. Select either Sync or Async pairs (not both). If you plan to use
the Resume Range option, select only one TC390A pair in the group.
5. Right-click to display the pop-up menu and click Resume Pair. The Resume Pair window is displayed.
6. From the Resume Pair window, select the appropriate pair options, and click Set to close the Resume
Pair window and set the parameters. The list changes to the Pair Settings Parameter list (Resume Pair).
Verify that all resume options and pair options for each pair are correct.
NOTE: The options can be modified and/or canceled after you have set them. See ”Modifying
Parameters and Omitting Selected Volumes” on page 117.
If you want to resume all split/suspended TC390A pairs in a consistency group, verify that the
Resume Range option on the Resume Pair window is set to Group.
7. If you want to execute the Resume Pair requests quickly, select the Use Time-Saving Mode check box
above the Pair Settings Parameter list (Resume Pair).
8. Click Apply on the TrueCopy main window to resume the specified pair(s).
9. From the TrueCopy main window, verify that the TC390 pair(s) is/are displayed correctly (Pending
duplex or Duplex status) in the Volume list.