Preferred server configurations are collections of one or more servers and sites that you select as preferred backup sources. Preferred server configurations take priority as backup sources in instances where database copies are replicated between multiple servers. You can create preferred server configurations for Microsoft Exchange Database Availability Groups (DAG).
You do not have to create a preferred server configuration to back up replicated database copies. You can let Backup Exec choose the best server from which to back up the replicated database copies. Designating a preferred server configuration gives you more control over your backup jobs. For example, you can select a local preferred server configuration to avoid having to back up replicated data over your WAN.
Backup Exec automatically includes the children of any site or DAG that you select as part of the preferred server configuration. So if you want to ensure that a backup is performed locally, you can select the local site as the preferred server configuration. Backup Exec selects from any of the local servers that belong to that site during the backup job. If you want to ensure that a specific server is used for the backup, select only that server as the preferred server configuration.
More Information
Creating preferred server configurations
Deleting preferred server configurations