6.5 HP StoreAll OS User Guide

The examples in the configuration rules use three StoreAll clusters: C1, C2, and C3:
• C1 has two file systems, c1ifs1 and c1ifs2, mounted as /c1ifs1 and /c1ifs2.
• C2 has two file systems, c2ifs1 and c2ifs2, mounted as /c2ifs1 and /c2ifs2.
• C3 has two file systems, c3ifs1 and c3ifs2, mounted as /c3ifs1 and /c3ifs2.
In the examples, <cluster name>:<target path> designates a replication target such as
C1:/c1ifs1/target1.
The following rules apply to intercluster replications:
• Remote replication is not supported between 6.1.x and 6.2 clusters in either direction if Express
Query is enabled on the 6.2 cluster.
• Only one continuous Remote Replication task can run per file system. It must replicate from
the root of the file system; you cannot continuously replicate a subdirectory of a file system.
• A continuous remote replication task can replicate to only one target cluster.
• Replication targets are directories in a StoreAll file system and can be:
The root of a file system such as /c3ifs1.◦
◦ A subdirectory such as /c3ifs1/target1.
Targets must be explicitly exported using CRR commands to make them available to CRR
replication tasks.
• A subdirectory created beneath a CRR export can be used as a target by a replication task
without being explicitly exported in a separate operation. For example, if the exported target
is /c3ifs1/target1, you can replicate to folder /c3ifs1/target1/subtarget1 if the
folder already exists.
• Directories exported as targets cannot overlap. For example, if C1 is replicating /c1ifs1 to
C2:/c2ifs1/target1, C3 cannot replicate /c3ifs1 to C2:/c2ifs1/target1/target2.
• A cluster can be a target for one replication task at the same time that it is replicating data to
another cluster. For example, C1 can replicate /c1ifs1 to C2:/c2ifs1/target1 and C2
can replicate /c2ifs2 to C1:/c1ifs2/target2, with both replications occurring at the
same time.
• A cluster can be a target for multiple replication tasks. For example, C1 can replicate /c1ifs1
to C3:/c3ifs1/target1 and C2 can replicate /c2ifs1 to C3:/c3ifs1/target2, with
both replications occurring at the same time.
• Continuous Remote Replication tasks can be linked. For example:
C1 replicates /c1ifs1 to C2:/c2ifs1/target1.◦
◦ C2 replicates /c2ifs1/target1 to C3:/c3ifs2/target2.
NOTE: If a different file system is used for the target, the linkage can go back to the original
cluster.
• To replicate a directory or snapshot on a file system covered by continuous replication, first
pause the continuous task and then initiate a run-once replication task.
For information about configuring intercluster replications, see “Configuring the target export for
replication to a remote cluster” (page 251).
250 Using continuous remote replication