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: Choose the DFSR server host as the client. See Adding, changing, or deleting clients in a policy. Choose ALL_LOCAL_DRIVES as the Directive in the Backup Selections for the policy. The ALL_LOCAL_DRIVES directive includes the Shadow Copy Components:\ automatically. See Adding backup selections to a policy. 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: Create a global exclude list for All Policies and All Schedules. Exclude the following DFSR top-level folder: `Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolder` The global exclude list ensures that the DFSR components are not backed up accidentally by other backup policies for the client. See Exclude list properties. Create a backup policy for the DFSR data, as follows: For the client, specify the DFSR server host. For the servers that are hosted in a cluster, specify the DFSR cluster name rather than the local host name. See Adding, changing, or deleting clients in a policy. For the Backup Selections for the policy, specify the absolute path to each of the top-level DFSR folders on that host. The following is an example path: `Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders\folder_name` Tip: Use the Backup, Archive, and Restore interface to browse the Shadow Copy Components for the `DfsrReplicatedFolders` folder. The interface shows the path to each DFSR folder that you need to enter as a backup selection. See Adding backup selections to a policy. For the backup policy, create an exception to the exclude list and specify the top-level DFSR directory, as follows: `Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders` For the exception Policy, specify the backup policy for the DFSR data. Also specify All Schedules for the Schedule. If DFSR is hosted in a cluster, create the exception for each host in the cluster. The exception ensures that the Shadow Copy Components DFSR paths are included for backup after NetBackup processes the global exclude list. See Add an exception to the exclude list.

Amount of data

Recommendation

Less than 50 GBs

Configure one policy as follows:

Choose the DFSR server host as the client.
See Adding, changing, or deleting clients in a policy.
Choose ALL_LOCAL_DRIVES as the Directive in the Backup Selections for the policy.
The ALL_LOCAL_DRIVES directive includes the Shadow Copy Components:\ automatically.
See Adding backup selections to a policy.

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:

Create a global exclude list for All Policies and All Schedules. Exclude the following DFSR top-level folder:
Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolder
The global exclude list ensures that the DFSR components are not backed up accidentally by other backup policies for the client.
See Exclude list properties.
Create a backup policy for the DFSR data, as follows:
- For the client, specify the DFSR server host. For the servers that are hosted in a cluster, specify the DFSR cluster name rather than the local host name.
  See Adding, changing, or deleting clients in a policy.
- For the Backup Selections for the policy, specify the absolute path to each of the top-level DFSR folders on that host. The following is an example path:
  Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders\folder_name
  Tip: Use the Backup, Archive, and Restore interface to browse the Shadow Copy Components for the DfsrReplicatedFolders folder. The interface shows the path to each DFSR folder that you need to enter as a backup selection.
  See Adding backup selections to a policy.
For the backup policy, create an exception to the exclude list and specify the top-level DFSR directory, as follows:
Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders
For the exception Policy, specify the backup policy for the DFSR data. Also specify All Schedules for the Schedule.
If DFSR is hosted in a cluster, create the exception for each host in the cluster.
The exception ensures that the Shadow Copy Components DFSR paths are included for backup after NetBackup processes the global exclude list.
See Add an exception to the exclude list.

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.

Restores of DFSR

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.

More information

https://support.cohesity.com/s/article/article-100038589

Refer to the Microsoft documentation on managing and using DFSR for additional details.

About Microsoft DFSR backups and restores

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