HP StorageWorks XP Remote Web Console Software - Manual (Page 34)

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. When you release a pair from the MCU, the MCU changes the status of the
M-VOL and R-VOL (if the path status is normal) to simplex. When you release a pair from the RCU,
the RCU changes the R-VOL status to simplex, and the MCU detects the pair release (if the path
status is normal) and changes the M-VOL status to suspended.
TrueCopy for Mainframe Asynchronous-Specific Pair Status
The TrueCopy for Mainframe Asynchronous suspending and deleting transitional states occur when
a request to change TrueCopy for Mainframe Asynchronous pair status has been accepted, but
the change to the requested status (suspended or simplex) is not yet complete. These states are not
reported to the host. In the case of suspending, both the user and the MCU can request the status
change. In the case of deleting, only the user can request the status change. If the user requested
the status change, the final status is reported at the end of the transition. If an error caused the
status to change to suspended, the suspended status is reported at the beginning of the transition.
The TrueCopy for Mainframe Asynchronous SEQCHK status is indicated when a TrueCopy for
Mainframe Asynchronous pair assigned to a consistency group with the System timer type accepts
a non-time-stamped update from the primary system. The SEQCHK status does not affect TrueCopy
for Mainframe Asynchronous copy activities and will be removed when the next time-stamped
update is successfully copied to the R-VOL. However, if a disaster or system failure occurs before
the next time-stamped update, the update sequence consistency between the R-VOL and other
R-VOLs in the consistency group is not ensured. To ensure effective disaster recovery, you should
detect and remove the source of the SEQCHK status. The SEQCHK status can be caused by any
of the following:
•
An application may issue update I/Os bypassing the MVS standard I/O procedure.
•
The I/O time-stamping function may not be active at the primary system.
Table 8 TrueCopy for Mainframe Pair Status
Description Pair Status
This volume is not currently assigned to a TrueCopy for
Mainframe pair. When this volume is added to a TrueCopy Simplex
for Mainframe pair, its status will change to pending
duplex.
The TrueCopy for Mainframe initial copy operation for this
pair is in progress. This pair is not yet synchronized. When
the initial copy is complete, the status changes to duplex. Pending Duplex
This pair is synchronized. Updates to the M-VOL are
duplicated on the R-VOL. Duplex
This pair is not synchronized: Suspended
(see “Suspend Types” (page 36) for suspend types) • For TrueCopy for Mainframe Synchronous only, if the
MCU cannot keep the pair synchronized for any reason,
the MCU changes the status of the M-VOL and R-VOL
(if possible) to suspended.
For TrueCopy for Mainframe Asynchronous only, if the
MCU detects a TrueCopy for Mainframe Asynchronous
suspension condition, the MCU changes the M-VOL
status and R-VOL status (if possible) to suspended.
• For TrueCopy for Mainframe Asynchronous only, when
the RCU detects a TrueCopy for Mainframe
Asynchronous suspension condition, the RCU changes
the R-VOL status to suspended.
• For TrueCopy for Mainframe Synchronous only, the
MCU changes the status of all TrueCopy for Mainframe
34 About TrueCopy for Mainframe Operations