HP XP24000/XP20000 Business Copy Software User Guide (T5213-96034, November 2011)

status during a normal pairresync operation is COPY(RS), and the P-VOL remains accessible
to all hosts for both read and write operations during a normal pairresync.
• Quick Resync (forward pairresync in fast speed)
The quick pairresync operation (see Figure 6 (page 16)) first reads the differential bitmap of
P-VOL and S-VOL, and changes the pair status to PAIR. The differential data based on the
differential bitmap will be copied when update copy operations are performed for the pair
in PAIR status. The pairresync operation by Quick Resync is faster than Normal Copy because
Quick Resync changes pair status to PAIR before actually copying differential data to the
S-VOL.
The pair status during a quick pairresync operation is COPY(RS). The P-VOL remains accessible
to all hosts for both read and write operations. The S-VOL becomes inaccessible to all hosts
during a quick pairresync operation.
Figure 6 (page 16) illustrates how the data changes during the forward pairresync operations.
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