HP StorageWorks XP Remote Web Console Software - Manual (Page 33)

by the Time Out [Copy Pending] group option, the MCU will suspend all affected pair(s) due to the
heavy I/O workload (at MCU or RCU). To prevent timeout errors, you can increase the Time Out
[Copy Pending] value, reduce I/O workload, and/or add remote copy resources.
This information is valid only when the timer type is System.
Group Operations
TrueCopy for Mainframe Async 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 (Group suspend option, supported by CSUSPEND
TSO command). ◦
◦ Resynchronize all suspended pairs in a consistency group (Group resynchronize option,
supported by the CESTPAIR TSO command with MODE=RESYNC).
◦ Release all pairs in a consistency group (Group release option, supported by CDELPAIR
TSO command).
•
Group operations at the RCU:
Suspend all pairs in a consistency group (Group suspend option, supported by CSUSPEND
TSO command). ◦
◦ Release all suspended pairs in a consistency group except for any inconsistent pairs (C/T
release option, not supported by CDELPAIR, CDELPAIR cannot be issued to the RCU).
◦ Release all pairs in a consistency group regardless of their consistency status (Group
release option, not supported by CDELPAIR, CDELPAIR cannot be issued to the RCU).
TrueCopy for Mainframe Asynchronous also provides the Error level pair option which is used to
trigger automatic suspension of an entire consistency group. When a TrueCopy for Mainframe
Asynchronous pair is suspended due to failure (not user-requested), this TrueCopy for Mainframe
Asynchronous pair option determines whether all pairs in the same consistency group will also be
suspended. If you select the Group error level for a TrueCopy for Mainframe Asynchronous pair,
all pairs in the same group will be suspended. If you select the Volume error level, only the affected
TrueCopy for Mainframe Asynchronous pair will be suspended.
The Error level pair option is very important for managing TrueCopy for Mainframe Asynchronous
groups and planning for disaster recovery. The Group error level should be selected for all TrueCopy
for Mainframe Asynchronous volumes which are essential to disaster recovery. Suspended TrueCopy
for Mainframe Asynchronous R-VOLs which have the Volume error level should not be used for
disaster recovery.
Pair Status
TrueCopy for Mainframe displays the pair status for each volume in the selected logical CU of the
connected HP disk array. 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 TrueCopy for Mainframe pair status
can be acquired from the MCU and RCU using the TrueCopy for Mainframe software (Pair Status)
and the CQUERY TSO command.
“TrueCopy for Mainframe Pair Status” (page 34) lists and describes the TrueCopy for Mainframe
pair status descriptions. A volume which is not assigned to a TrueCopy for Mainframe pair has
the status simplex. When a TrueCopy for Mainframe 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,
Pair Status 33