Understanding custom replication scripts

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Part Number

Under normal conditions, pre- and post-replication scripts are not required. Where required to perform specific functions (for example, to stop an application to facilitate a snapshot of its files in a quiescent, consistent state), these custom scripts can be run before or after each instance of a replication.

In the case of a database or other application that requires a consistent state at the time of a snapshot, best practices suggest using scripts and snapshot rules together:

  • Pre-replication scripts are executed to completion before the replication is started.
  • Post-replication scripts are executed after a successful replication.

Potential uses of scripts are illustrated in the following examples:

  • Database replication. A pre-replication script can be used to enable the replication of a consistent copy of the database. Typically, this pre-replication script will need to:
    1. Shut down the database to bring it into a consistent or quiescent state.
    2. Take a snapshot of the file system using a snapshot rule.
    3. Restart the database.
  • Backing Up Data from the Replication Target. A post-replication script can initiate incremental (or full) backups from a replication target after each incremental replication has completed. Backing up from the replication target (rather than the original volume or directory) minimizes the performance impact on network users.