About Microsoft DFSR backups and restores
NetBackup protects the databases that are associated with the independent DFSR servers and the DFSR data.
In an environment that has DFSR, two changes occur in NetBackup, as follows:
To preserve data integrity, the folder or folders that host the Shared Replica DFSR data are excluded automatically by NetBackup from normal file system backups.
The top-level DFSR shared folders become part of the Shadow Copy Components. Therefore, the data is snapped consistently by Windows Volume Shadow Copy Service (VSS) before each backup.
The VSS writer stops and restarts the DFS Replication service automatically. Schedule the backups to coincide with a period of low activity. (If you stop the replication service manually, Microsoft change journal problems may occur. Specifically, Update Sequence Number (USN) Journal wrap may occur.)
By default all Windows clients are configured for Windows open file backups. The DFSR servers must be configured for this option.
See Windows open file backup tab of the Client attributes properties.
Refer to Table: Microsoft DFSR backup recommendations recommendations on how to back up DFSR data.
Table: Microsoft DFSR backup recommendations
Amount of data | Recommendation |
|---|---|
|
Less than 50 GBs |
Configure one policy as follows:
One policy can back up the data within a reasonable time window. |
|
More than 50 GBs |
Configure one backup policy for each DFSR server, and in that policy specify only the replication folders. A policy for each host's replication data ensures that the DFSR data is backed up within a reasonable time window. For each DFSR server host, do the following:
|
During a backup, Windows writes the following event ID messages to the application event log of a DFSR host:
Event ID=1102 Severity=Informational The DFS Replication service has temporarily stopped replication because another application is performing a backup or restore operation. Replication will resume after the backup or restore operation has finished.
Event ID=1104 Severity=Informational The DFS Replication service successfully restarted replication after a backup or restore operation.
To restore DFSR data, use the NetBackup Backup, Archive and Restore client interface to browse the Shadow Copy Components for the files or folders to restore, as follows:
Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders\folder_name
When you perform a restore, consider carefully if the restore needs to include the DFSR database, in addition to the DFSR data. A DFSR server maintains a globally unique version number (GVSN) for each DFSR database on each replicated volume. If you restore a DFSR server to an earlier database version, the other servers do not recognize the older version number. Then replication is impossible and stops until the issue is corrected.
Refer to the Microsoft documentation on managing and using DFSR for additional details.