HP StorageWorks Continuous Access EVA Administrator Guide (T3687-96043, December 2005)

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1. Host server
2. Switch
3. Host I/O
4. Replication writes
5. Local array
6. Remote array
7. Source virtual disk 8. Destination virtual disk
9. Source and destination DR groups
Figure 1 DR group replication
DR gr
oup log
The DR group log is a designated virtual disk that stores a source DR group's host writes while replication
to the destination DR group is stopped. This pro cess is called logging. Replication can be stopped
bec
ause the destination DR group is unavailable o r because the DR group is suspended. When
rep
lication resumes, the contents of the log are written to the destination virtual disks. This method of
synchronizing destination virtual disks with source virtual disks is called merging. B ecause the data is
writ ten to the destination in the order that it was written to the log, merging m aintains a crash consistent
co
py at the destination. The DR group l og is created when you create a DR group.
HP StorageWorks Continuous Access EVA administrator guide
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