You should always back up your Microsoft Exchange Server computers so that you can restore servers with minimum downtime in the event of a disaster.
Use Windows NT Backup to back up the information store and directory. In addition, keep records of critical Windows NT settings such as the production server Internet Protocol (IP) address information and computer name. Note that some optional components, such as the Key Management server (KM server), have their own backup procedures.
You need only back up and restore the directory and information store because other components (such as the MTA and Microsoft Mail Connector) contain highly transient data. For example, backing up the MTA records messages that are delivered seconds after the backup; therefore, restoring this information might result in duplicate messages.
Note Any values you have manually configured in the Windows NT Registry should be reconfigured after reinstalling Microsoft Exchange Server.
For information about backing up servers, restoring the information store, and restoring the directory, see Chapter 12, "Disaster Recovery," and Microsoft Exchange Server Maintenance and Troubleshooting.