HP XP Racks User Manual
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Figure 14 Example of a 3DC Cascade (Cnt Ac-J Z x Cnt Ac-J Z) configuration
Performing journal-based asynchronous copying (by using Continuous Access Journal Z) between
sites can reduce the I/O load on the host. In addition, because Continuous Access Journal Z
operations are performed through the intermediate site, remote sites can be placed at more distant
locations than those in a 3DC Cascade (Cnt Ac-S Z x Cnt Ac-J Z) configuration. This reduces the
risk of damage to all the sites if a disaster occurs.
The 3DC Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z) configuration
The primary site in a 3DC Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z) configuration performs normal
Continuous Access Synchronous Z and Continuous Access Journal Z operations, as well as remote
copy operations to apply application data to a nearby local site and a distant remote site.
shows an example of a 3DC Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z) configuration.
Figure 15 A 3DC Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z) configuration example
NOTE:
While the primary site is operating normally, hosts at the local and remote sites need not
be used.
Operations during local or remote site storage system maintenance or a failure
As shown in
and
, during local or remote site storage
system maintenance or a failure, the configuration can be changed to a 2DC configuration without
stopping the operations at the primary site.
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Business Continuity Manager with replication products