HP XP Business Copy Software - Manual (Page 19)

Business Copy XP user guide for the XP128/XP1024 19
Pairresync operations
To change the status of the pairs from PSUS to PAIR, or from PSUE to PAIR, you must resynchronize the
pairs. BC can perform the following types of pairresync operations according to the speed and direction of
the resynchronization:
• Normal Copy
• Quick Resync
• Reverse Copy
• Quick Restore
Use the Pairresync pane to resynchronize split and suspended BC pairs. When the pairresync operation
starts, the pair status changes to COPY(RS) or COPY(RS-R). When the pairresync is complete, the pair
status changes to PAIR. The local disk array resumes BC update copy operations after the pair status
changes to PAIR. The P-VOL remains fully accessible during a normal pairresync operation, but is
inaccessible to all hosts during a reverse or quick restore pairresync operation. This ensures that data on
the P-VOL is identical to data on the S-VOL when the reverse or quick restore pairresync operation
completes.
NOTE: You can use BC to perform normal or quick pairresync operations on split and suspended pairs,
but you can perform reverse or quick restore pairresync operations only on split pairs.
Forward pairresync operation
A forward pairresync operation resynchronizes pairs by copying data on P-VOLs to S-VOLs. The following
are the types of forward pairresync operations:
• Normal. This operation (see Figure 4) resynchronizes the S-VOL with the P-VOL. The copy direction for a
normal pairresync operation is P-VOL to S-VOL. The pair status during a normal resync operation is
COPY(RS), and the P-VOL remains accessible to all hosts for read and write operations during a normal
pairresync.
• Quick. This operation speeds up the normal pairresync operation without copying the P-VOL data to the
S-VOL. The P-VOL and S-VOL are resynchronized when update copy operations are performed for
duplex pairs (status = PAIR). The pair status during a quick pairresync operation is PSUS(SP) until the