Performing a Nonauthoritative Restore

The nonauthoritative restore (D2) is used to bring the local FRS replica set back up to date with its partners. Nonauthoritative restores are often necessary to resolve the following issues:

• Assertions in the FRS service
• Corruption of the local FRS jet database
• Journal wrap errors
• FRS replication failures

The nonauthoritative restore process brings a replica member up to date by comparing all the local files in a replica set with the ones of the upstream partners. After you set the Burflag to D2 and restart the service, FRS will move all the data into a "pre-existing" directory and then start to compare the file IDs and the files’ MD5 checksums from the upstream partner with the local ones. If the file ID and the MD5 checksum match, FRS copies this file from the pre-existing directory into its original location. If they don’t match, then FRS copies the new file from the partner. Before Windows 2000 SP3, this work is performed with each of upstream partner at once; with Windows 2000 SP3 and later and Windows Server 2003, this process is performed sequentially — one partner at a time.

To perform a nonauthoritative restore, use the following procedure:

To perform a nonauthoritative restore

1. At the command prompt, type net stop ntfrs.
2. Click Start, click Run, type regedit, and then click OK.
3. Locate the following subkey in the registry:

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NtFrs\Parameters\ Backup/Restore\Process at Startup

4. In the right pane, double-click BurFlags.
5. In the Edit DWORD Value dialog box, type D2 and then click OK.
6. Close Registry Editor.
7. At the command prompt, type net start ntfrs.

When the FRS service restarts, the following actions occur:

• The value for BurFlags registry key returns to 0.
• Files in the reinitialized FRS folders are moved to a folder named NtFrs_PreExisting_See_EventLog.
• The FRS database is rebuilt.
• The member performs an initial join of the replica set from an upstream partner or from the computer that is specified in the Replica Set Parent registry key if a parent has been specified for SYSVOL replica sets.
• The reinitialized computer performs a full replication of the affected replica sets when the relevant replication schedule begins.

The placement of files in the NtFrs_PreExisting_See_EventLog folder on reinitialized members is a safeguard in FRS designed to prevent accidental data loss. Any files destined for the replica that exist only in the local PreExisting folder and did not replicate in after the initial replication can then be copied to the appropriate folder. When outbound replication has occurred, delete files in the PreExisting folder to free up additional disk space.

For more information about performing a nonauthoritative restore, see article 290762, "FRS: Using the BurFlags Registry Key to Reinitialize File Replication Service Replica Sets" at http://support.microsoft.com/?id=290762.