How Backup Exec works in a Microsoft Cluster Server environment
When you install Backup Exec into a Microsoft cluster, you install it as a virtual server application. You assign an IP address resource, a Network Name resource (the virtual server name), and a disk resource to Backup Exec.
When a failover occurs, backup jobs that were running are rescheduled. The Backup Exec services are restarted on a designated failover node, and the backup jobs are restarted by default. Backup Exec provides an additional rule for cluster failover restart called Checkpoint Restart. A checkpoint restart option allows backup jobs to continue from the point at which the jobs were interrupted rather than starting the backup over again, making the backups faster and requiring fewer media. If the rule to retry jobs on a cluster failover is enabled, then an additional option can be specified to do a checkpoint restart when retrying the job. Checkpoint Restart is the only property available for the Cluster Failover Rule. You can change the default so that jobs are not restarted.
When the failed server comes back online, the Microsoft cluster can automatically rebalance the workload in a cluster, called failback, by moving cluster groups back to the server that has rejoined the cluster. However, by design, Backup Exec does not failback. The backup jobs will continue to run on the designated failover node. By continuing to run backup jobs on the designated failover node, any further risk of having to restart the jobs again when the failed server rejoins the cluster is avoided. Then, when it is convenient, you can move the Backup Exec cluster group back to the controlling node.