USN Journal Wrap

FRS event ID 13568 occurs when the specified replica member enters a journal wrap condition. The NTFS file system maintains a special log called the USN journal, which is a high-level description of all the changes to files and directories on an NTFS volume. FRS uses this mechanism to track changes to the file system in directories of interest, and queue those changes for replication to other computers.

The USN journal has defined size limits and will discard old log information on a first in, first out basis to maintain its correct size. If FRS processing falls behind the USN journal, and if USN journal information that FRS needed has been discarded, then FRS enters a journal wrap condition. FRS then needs to rebuild its current replication state with respect to the file system and other replication partners.

FRS can encounter USN journal wrap conditions in the following cases:

• Many files are added at once to a replica tree while FRS is very busy, starting up, or not running.
• On a server that is being used for authoritative restore, or as the primary for a new replica partner, there is a lot of file activity at the start of this process and this can consume USN journal records.
• An NTFS volume needs to be processed with Chkdsk, and Chkdsk corrects the file system structure. In this case, NTFS creates a new USN journal for the volume or deletes the corrupt entries from the end of the journal.
• The USN journal is deleted or reduced in size.
• The FRS service is in an error state that prevents it from processing changes in the USN journal.

Resolution

If FRS is experiencing journal wrap errors on a particular server, it cannot replicate files until the condition has been cleared. To continue replication, you must stop FRS on that server and perform a nonauthoritative restore of the data so that the system can synchronize with its replication partners. Note the following about nonauthoritative restores:

• Windows 2000 SP1 cannot perform this process automatically.
• In Windows 2000 SP2, FRS performs this process automatically.
• In Windows 2000 SP3 and later and Windows Server 2003, FRS does not perform this process automatically. The reason for this change was that it was typically being performed at times that were not planned by administrators. However, there is a registry setting available that allows FRS to perform the automatic nonauthoritative restore, just as in Windows 2000 SP2. However, Microsoft recommends leaving this as a manual process.

For more information about nonauthoritative restores, see Performing a Nonauthoritative Restore.

For information about sizing the USN journal to avoid journal wraps, see Adjust the USN Journal Size Accordingly.