About protecting SQL Server availability groups
NetBackup for SQL Server supports backups and restores of SQL Server Always On and read-scale availability groups. For information on supported versions and environments, see the Application/Database Agent Compatibility List.
You can protect an availability group environment in the following ways:
With a protection plan that protects the preferred or the primary replica.
With a policy that protects the preferred or the primary replica.
If an availability group crosses multiple NetBackup domains, you can use Auto Image Replication (A.I.R.) to replicate the backup to the other NetBackup domains.
See Protect a SQL Server availability group that crosses NetBackup domains with a policy.
Note the following before you configure the policy or the protection plan:
NetBackup can only fully protect the availability group environment if each replica on which backups occur is registered with credentials.
NetBackup runs a backup job on each replica in the availability group. On the replicas which are not the backup source, the job skips the backup.
NetBackup does not support the following types of backups for availability databases:
Snapshot backups of filegroups or files
Instant Recovery backups (configured with policies)
VMware backups
SQL Server does not support the following types of backups on a secondary replica:
Full backups
If a full backup takes place on a secondary replica, NetBackup converts the full backup to a copy-only backup.
Certain differential backups that are performed with a SQL Server Intelligent policy.
A differential backup is skipped when an availability group is added as a backup selection.
A differential backup fails when an availability database is added as a backup selection.
A differential backup that is performed with a batch file-based policy.
Backups of this type result in a failed backup.
Copy-only transaction log backups
Backups of this type result in a failed backup.
(SQL Server 2022) An issue exists with filegroup backups for the replicas that participate in an Always On availability group that is marked as non-readable. They are not supported at this time due to a Microsoft limitation.