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

36 TrueCopy for the XP1024/XP128/XP12000/XP10000
can increase the Time Out [Copy Pending] value, reduce I/O workload, and/or add remote copy
resources.
Group Operations
TC390A provides the following group-based operations to simplify and expedite disaster/failure recovery
procedures:
• Group operations at the MCU:
• Suspend all pairs in a consistency group. For a description of the TC390A Group suspend option
(supported by CSUSPEND TSO command), see ”Suspending TrueCopy Pairs (Suspend Pair)” on
page 126.
• Resume all suspended pairs in a consistency group. For a description of the TC390A
Resume-Group pair option (supported by the CESTPAIR TSO command with the parameter
MODE=RESYNC), see ”Resuming TrueCopy Volume Pairs (Resume Pair)” on page 129.
• Delete all pairs in a consistency group. For a description of the TC390A Group delete option
(supported by CDELPAIR TSO command), see ”Deleting TrueCopy Volume Pairs (Delete Pair)” on
page 132.
• Group operations at the RCU:
• Suspend all pairs in a consistency group. For a description of the TC390A Group suspend option
(supported by CSUSPEND TSO command), see ”Suspending TrueCopy Pairs (Suspend Pair)” on
page 126.
• Delete all suspended pairs in a consistency group except for any inconsistent pairs. For a
description of the TC390A C/T delete option (not supported by CDELPAIR, CDELPAIR cannot be
issued to the RCU), see ”Deleting TrueCopy Volume Pairs (Delete Pair)” on page 132.
• Delete all pairs in a consistency group regardless of their consistency status. For a description of the
TC390A Group delete option (not supported by CDELPAIR, CDELPAIR cannot be issued to the RCU),
see ”Deleting TrueCopy Volume Pairs (Delete Pair)” on page 132.
TC390A also provides the Error level pair option (see ”Creating TrueCopy Volume Pairs (Add Pair)” on
page 121) that is used to trigger automatic suspension of an entire consistency group. When a TC390A
pair is suspended due to failure (not user-requested), this TC390A pair option determines whether all pairs
in the same consistency group will also be suspended. If you select the Group error level for a TC390A
pair, all pairs in the same group will be suspended. If you select the Volume error level, only the affected
TC390A pair will be suspended.
NOTE: The Error level pair option is very important for managing TC390A groups and planning for
disaster recovery. The Group error level should be selected for all TC390A volumes that are essential to
disaster recovery. Suspended TC390A R-VOLs that have the Volume error level should not be used for
disaster recovery.
TrueCopy Volume Pair Status
TC390A displays the pair status for each volume in the selected logical CU image (CUI) of the connected
XP1024/XP128/XP12000/XP10000. The MCU maintains the status of the M-VOL and is responsible for
keeping the M-VOL and its R-VOL synchronized. The RCU maintains the status of the R-VOL. The MCU can
change the pair status of the M-VOL and R-VOL. The RCU can change the pair status of the R-VOL but not
the M-VOL. The MCU will detect when the RCU changes the R-VOL status (if the path status is normal) and
will change the M-VOL status accordingly. The TC390 pair status can be acquired from the MCU and RCU
using the TC390 software (Pair Status) and the CQUERY TSO command.
Table 9 on page 37 lists and describes the TC390 volume pair status descriptions. A volume that is not
assigned to a TC390 volume pair has the status simplex. When a TC390 pair is started, the MCU changes
the status of both volumes (M-VOL and R-VOL) to pending duplex. When the initial copy operation is
complete, the MCU changes the status of both volumes to duplex. When a pair is suspended from the
MCU, the MCU changes the status of the M-VOL and R-VOL (if the path status is normal) to suspended.
When a pair is suspended from the RCU, the RCU changes the status of the R-VOL to suspended, and the
MCU detects the pair suspension (if the path status is normal) and changes the M-VOL status to suspended.