The specifics of a disaster recovery scenario vary depending on the organizational requirements, how Messaging Gateway (SMG) is being used in the environment, and the hardware / virtual platform in use. In general, SMG recovery is dependent on
The ability to restore the system to a factory default state via osrestore
The ability if relicense the product if needed
The ability to restore data and configuration
Preparing the SMG for disaster recovery is a multi-step process. Ensure that you have all the licensing and technical components to exactly mirror your previous configuration and administration. Additionally, it is an industry best practive to perform schedule "test runs" of disaster recover procedures to document any gaps or issues with the process.
NOTE: If using virtual machines, snapshots may be used for disaster recovery provided that the snapshot is taken with the virtual machine fully shut down and quiesced. Symantec strongly discourages taking snapshots of a running SMG virtual machine as this may lead to issues with system operation and re-deploying the snapshot.