6.3 HP StoreAll Storage File System User Guide (TA768-96093, June 2013)

• 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 180).
Using intracluster replications
There are two forms of intracluster replication:
• The same cluster and a different file system. Configure either continuous or run-once replication.
You will need to specify a target file system and optionally a target directory (the default is
the root of the file system or the mount point).
• The same cluster and the same file system. Configure run-once replication. You will need to
specify a file system, a source directory, and a target directory. Be sure to specify two different,
non-overlapping subdirectories as the source and target. For example, the following replication
is not allowed:
From <fs_root>dir1 to <fs_root>dir1/dir2
However, the following replication is allowed:
From <fs_root>dir1 to <fs_root>dir3/dir4
File system snapshot replication
You can use the run-once replication mode to replicate a single file system snapshot. If a snapshot
replication is not explicitly configured, snapshots and all related metadata are ignored/filtered
out during remote replications. Replication is not supported for block snapshots.
Configuring the target export for replication to a remote cluster
Use the following procedure to configure a target export for remote replication. In this procedure,
target export refers to the target file system and directory (the default is root of the file system)
exported for remote replication.
Planning Considerations
When planning for StoreAll Continuous Replication, consider the following:
• All changes on the source are replicated to the target, including creation or deletion of files
and directories, whether planned or accidental. File system snapshots can be used on the
source and target clusters to protect against accidental file deletion.
• If you only change the attributes of a file or directory, only the attribute changes are replicated.
This includes changes to extended attributes.
• If you make any updates to the data blocks of a previously replicated file the entire file is
replicated again, not just the changed blocks in the file.
180 Using remote replication