Hitachi ShadowImage for z/OS user guide (HIT9503-96004, June 2006)

136 ShadowImage for the XP1024/XP128/XP12000/XP10000
• If data on the shared memory is not volatilized and not lost:
The status before powering off will be maintained. As for the relationships in COPY mode, background
copying will automatically restart when you power on the disk array.
• If data on the shared memory is volatilized and lost:
If relationships exist before powering off the disk array, the T-VOLs will become blocked and
inaccessible from hosts when you power on the disk array. Thus, the host does not access the
inconsistent data in the T-VOLs. To restore the T-VOLs to normal status, force restoration of LDEVs.
NOTE: If the T-VOL is an external volume, the disk subsystem may start normally and the T-VOL may not
become blocked even if data on the shared memory is lost. However, although the disk subsystem starts
normally, it is feared that data in the T-VOL is not normal. Therefore, you should delete data in the T-VOL or
initialize the T-VOL.
• First complete the processing of At-Time Split function, and then switch off the power supply.
NOTE: If the status of only a part of the pairs in the same consistency group is changed, the processing of
At-Time Split function may not resume when you switch on the power supply, and the status of some pairs
may remain unchanged.
CAUTION: If data on the shared memory is volatilized and lost after the power turns on, problems
may occur during operations. To avoid possible problems, withdraw as much relationships as
possible before powering off the disk array.
Suspending FlashCopy Mirror Version 2 Pairs
FlashCopy Mirror Version 2 pairs may be suspended if a hardware or software failure occurs during
FlashCopy Mirror Version 2 operation. If FlashCopy Mirror Version 2 pairs are suspended, hosts may be
unable to access copy target datasets.
To find whether suspended FlashCopy Mirror Version 2 pairs exist within the volumes, use the
ShadowImage z/OS main panel (see ”ShadowImage Main Window” on page 44). If the Relation(s)
column of the volume list displays S-Failed or T-Failed, a suspended FlashCopy Mirror Version 2 pair exists
within the volume.
To delete a suspended FlashCopy Mirror Version 2 pair, do one of the following:
• Delete the copy target dataset that have the suspended FlashCopy Mirror Version 2 pair (i.e., the
dataset that is inaccessible from hosts). The operating system will automatically recognize the pair that
has the dataset to be deleted, and will issue the Withdraw command.
• Issue the TSO FCWITHDR command. If the suspended FlashCopy Mirror Version 2 pair can be
identified, please issue the FCWITHDR command to its extent. For detailed information about the
FCWITHDR command, see ”Withdrawing FlashCopy Mirror Version 2 Pairs: FCWITHDR” on
page 123.