3.7.0 HP StorageWorks HP Scalable NAS File Serving Software administration guide - HP Scalable NAS 3.7 for Linux (AG513-96002, October 2009)

14 Configure and manage replication
Overview
HP Scalable NAS provides tools and processes to enable automatic replication of
the data in your PSFS filesystems. During replication, data in specific filesystems or
directories on the source cluster is transferred to another cluster called the destination
cluster.
Before using replication, you will need to create an administrative filesystem and
install a matching ssh key pair on both the source and destination clusters. You will
also need to create a configuration file that specifies information such as the filesystems
and directories to be replicated and the time between replications (the replication
interval).
When replication has been configured, the replication program is started automatically
when HP Scalable NAS is started. When a replication interval begins, a replication
program verifies that the filesystems to be replicated are mounted.
IMPORTANT:
All replication set source directories must be mounted on every node that is running
replication.
The replication program also monitors the filesystems and directories for any changes
and creates log files specifying files that have been added, modified, or deleted
during the replication interval. At the end of the interval, the new and changed files
are transferred to the destination cluster via rsync. (If a file already exists on the
destination cluster, only the changes in the file will be transferred.) Files that were
deleted from the source cluster are also deleted from the destination cluster. rsync
is configured to use compression (this setting cannot be changed.)
Replication stores its state information in the mxds datastore on the membership
partitions. The replication configuration is also kept in the mxds datastore.
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