HP XP Command View Advanced Edition Software - Manual (Page 416)

Figure 120 Processing flow for restoring storage groups from tape
Backing up storage groups to tape
Resynchronizing copy groups
When usual operation is in the split state, resynchronize the copy group before backing up the data.
When usual operation is in the pair status, there is no need to resynchronize the copy group before
backing up data. Instead, when the tape backup is complete, resynchronize the copy group to initialize
it.
To resynchronize a copy group:
1. Clear the cache of the secondary volume.
Before performing backup, clear the system cache of the backup server.
To clear the system cache, execute EX_DRM_CACHE_PURGE on the backup server and mount
and then unmount the secondary volume. In this example, the copy group name is VG01,vol01 .
BKServer > EX_DRM_CACHE_PURGE Operation_A -cg VG01,vol01
2. Resynchronize the copy group.
Execute EX_DRM_RESYNC on the database server to resynchronize the copy groups. If there is
a big difference between the primary volume data and the secondary volume data when data
is backed up from the primary volume to the secondary volume, the backup might take a while.
Resynchronizing the copy group before backing up data will help reduce the backup time.
DBServer > EX_DRM_RESYNC Operation_A -cg VG01,vol01 -copy_size 7
Operation for Exchange databases 416