Backup of Failover Clusters

Backing Up Entire Clusters

The recommended way to protect a failover cluster with Veeam Agent is a dedicated failover cluster backup job managed by Veeam Backup & Replication. In this mode, Veeam Agent is cluster-aware and treats the whole cluster as the backup source, which gives you the following benefits:

• Clustered disks stay in the same backup chain when they move between nodes. Failover does not trigger a full backup.
• The cluster job writes one backup chain per cluster, so blocks of clustered disks are stored once rather than once per node.
• Microsoft SQL Server Always On availability groups and failover cluster instances are supported in transaction log backup.

For setup and configuration, see the Creating Job for Windows Computers section in the Veeam Backup & Replication User Guide.

Backing Up Cluster Nodes as Individual Computers

If you want to back up cluster nodes as individual computers, keep in mind that Veeam Agent is not cluster-aware: it does not track cluster disks across nodes or handle failover. On each node, Veeam Agent backs up only the disks currently attached to that node, and whenever a disk arrives on a node that has no previous state for it — for example, after failover — Veeam Agent starts a new backup chain from a full backup.

If you decide to protect a cluster node as an individual computer, consider the following:

• Volume-level backup, file-level backup and transaction log truncation run as regular backup jobs — but only until failover. Veeam Agent has no way to follow a clustered resource once it moves off the node, so the affected disks drop out of the source node's backup as soon as failover happens.
• On each node, Veeam Agent maintains an independent backup chain for the disks that node currently holds. As the same clustered disks move between nodes, the same data may end up copied into several chains, which increases storage consumption in the repository and, correspondingly, the volume of data written over the network during backup.
• The backup job will fail if the node no longer holds any disk from the backup scope. Veeam Agent backs up only the disks physically attached to the node it runs on, so if all the in-scope disks have been failed over to another node, there is nothing left for the local backup to process.
• Transaction log backup is disabled and not supported when Veeam Agent is installed on a machine that is a Microsoft SQL Server Always On availability group node. Log backup in an Always On configuration requires availability group awareness, which Veeam Agent does not have.
• Because Veeam Agent is not cluster-aware when it backs up cluster nodes as individual computers, it cannot track cluster node state changes such as failover, resource moves, or role changes. As a result, the backup may not reflect the current cluster state.