Earlier this week i was tasked with troubleshooting the DFS replication for a development environment at work. I figured the issue was related to staging quota settings, so i ran a DFS Replication Health Report.
After reviewing the report i found the following error:
A USN journal wrap occurred 1 times in the past 7 days on E:. DFS Replication monitors the USN journal to detect changes made to the replicated folder. A USN journal wrap occurs when large numbers of files change so quickly that the USN journal must discard the oldest changes (before DFS Replication has had a chance to detect the changes) to stay within the specified size limit of the USN journal. Although DFS Replication automatically recovers from this problem, replication stops temporarily for replicated folders stored on this volume. Repeated journal wraps usually indicate that the USN journal is too small. Event ID: 2202
After a quick search i was able to find the tool to change the USN journal size and report on current settings. FSUTIL seems to be used for quite a bit more than hardlinks etc.
I found an article that touched on what what happening but unfortunately didnt work as it was for windows 2000 server.
http://support.microsoft.com/kb/292438
Here is how you determine the Max size of the USN journal (be sure to replace your drive letter at the end of the command)
fsutil usn queryjournal e:
my results from this command looked like this:
C:\Windows\system32>fsutil usn queryjournal e:
Usn Journal ID : 0x01cbceef195bdf41
First Usn : 0x0000000275c00000
Next Usn : 0x0000000295e3d420
Lowest Valid Usn : 0x0000000000000000
Max Usn : 0x7fffffffffff0000
Maximum Size : 0x0000000020000000
Allocation Delta : 0x0000000000400000
I decided to adjust the value to 2gb and see what happens. The following steps are needed to complete this change:
run the following command from the server with the drive you wish to change the USN journal size
fsutil usn createjournal m=2147483648 a=1 e:
Notice the drive letter is at the end of the command, so enter your drive letter here.
I used the microsoft calculator in programmer mode to convert HEX to decimal and then used an online bit calculator to convert the output to use in the command
http://www.matisse.net/bitcalc/
If you run the command again to query the journal your output would look like this:
C:\Windows\system32>fsutil usn queryjournal e:
Usn Journal ID : 0x01cbceef195bdf41
First Usn : 0x0000000278800000
Next Usn : 0x0000000298a8dab0
Lowest Valid Usn : 0x0000000000000000
Max Usn : 0x7fffffffffff0000
Maximum Size : 0x0000000080000000
Allocation Delta : 0x0000000000400000
I will post later about the results from this change. according to what i read online it will either fix the issue or require a larger USN journal. If anyone knows the max setting i would love to know them
Hopefully this information helps someone looking for the solution to DFS replication issues on windows 2008 R2.