Operating System Software Owner manual

4. saves the active snapshot, which enables Remote Copy to perform a fast resynchronization
later [Figure 40 (page 200)]
Figure 39 Full Synchronization Using Primary Volume Snapshots (Asynchronous Periodic Mode)
Resychronization
Remote Copy performs a resynchronization if both:
• The primary volume was previously synchronized, and
• A valid (up-to-date) resynchronization snapshot exists.
When performing a resynchronization (Figure 40 (page 200)), Remote Copy:
1. takes a snapshot of the data in the primary volume
2. compares the most recent resynchronization snapshot and the current synchronization snapshot
and determines the changes that occurred between the creation of each snapshot
3. transmits only the changes between snapshots to the secondary volume
4. after synchronization completes, deletes the snapshots created on the backup system
The base volumes now represent a valid point-in-time copy.
5. deletes the old resynchronization snapshot
Asynchronous Periodic Mode Volume Groups 199