HP Hitachi ShadowImage for Mainframe User Guide (T5213-96032, November 2011)

for the edited differential bitmap. The copy direction for a normal resync operation is S-VOL
to T-VOL. Pair status changes to Duplex when the copying process of differential data is
completed.
The pair status during a normal resync operation is resync, and the S-VOL remains accessible
to all hosts for both read and write operations during a normal resync operation. The T-VOL
becomes inaccessible to all hosts during a normal resync operation.
• Quick Resync (forward pairresync in fast speed)
The quick resync operation first edits the differential bitmap of S-VOL and T-VOL, and change
the pair status to Duplex when the editing process completes. The differential data based on
the information for the edited differential bitmap will be copied when update copy operations
are performed for duplex pairs (see Figure 6 (page 16)). The resync operation by Quick
Resync is faster than Normal Copy since Quick Resync changes pairs status to Duplex before
actually copying differential data to the T-VOL.
The pair status during a quick resync operation is resync, and the S-VOL remains accessible
to all hosts for both read and write operations. The T-VOL becomes inaccessible to all hosts
during a quick resync operation.
Figure 6 (page 16) illustrates how the data changes during the forward pairresync operations.
ShadowImage for Mainframe Operations 15