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

Replicating WORM/retained files
When using remote replication for file systems enabled for data retention, the following requirements
must be met:
• The source and target file systems must use the same data retention mode (Enterprise or
Relaxed).
• The default, maximum, and minimum retention periods must be the same on the source and
target file systems.
• A clock synchronization tool such as ntpd must be used on the source and target clusters. If
the clock times are not in sync, file retention periods might not be handled correctly.
Also note the following:
• Multiple hard links on retained files on the replication source are not replicated. Only the first
hard link encountered by remote replication is replicated, and any additional hard links are
not replicated. (The retainability attributes on the file on the target prevent the creation of any
additional hard links). For this reason, HP strongly recommends that you do not create hard
links on files that will be retained if you wish to replicate them.
• For continuous remote replication, if a file is replicated as retained, but later its retainability
is removed on the source file system (using the ibrix_reten_adm -c command or the File
Administration panel on the Management Console), the new file’s attributes and any additional
changes to that file will fail to replicate. This is because of the retainability attributes that the
file already has on the target, which cause the file system on the target to prevent remote
replication from changing it. If necessary, use data retention management commands on the
corresponding file on the target to make the same changes.
• When a legal hold is applied to a file (using the ibrix_reten_adm -h command or the
File Administration panel on the Management Console), the legal hold is not replicated on
the target. If the file on the target should have a legal hold, you will also need to set the legal
hold on that file. Likewise, you will need to release legal hold on the source and target file
separately.
• If a file has been replicated to a target and you then change the file's retention expiration
time with the ibrix_reten_adm -e command or the File Administration panel on the
Management Console, the new expiration time is not replicated to the target. If necessary,
also change the file's retention expiration time on the target.
Configuring remote failover/failback
When remote replication is configured from a local cluster to a remote cluster, you can fail over
the local cluster to the remote cluster:
1. Stop write traffic to the local site.
2. Wait for all remote replication queues to drain.
3. Stop remote replication on the local site.
4. Reconfigure shares as necessary on the remote site. The cluster name and IP addresses (or
VIFs) are different on the remote site, and changes are needed to allow clients to continue to
access shares.
5. Redirect write traffic to the remote site.
When the local cluster is healthy again, take the following steps to perform a failback from the
remote site:
1. Stop write traffic to the remote site.
2. Set up Run-Once remote replication, with the remote site acting as the source and the local
site acting as the destination.
Replicating WORM/retained files 193