Though Backup Exec can be used in a rolling upgrade configuration with older Agent versions during the upgrade process (see the Software Compatibility List in the Related Documents Section for more information), a warning message will be displayed when making remote backup selections or in the job log once a job has been created, when older Agents are used.  Backups and restores can usually continue normally until the Remote Agents are upgraded, but new features will be disabled until the Agent has been upgraded to the same version as the Backup Exec media server.

Note: Backups and restores with a rolling upgrade should only be done on a temporary basis and the Remote Agents should be upgraded as soon as possible to assure optimal backup and restore performance.