DFSR replication issue

Question

I have two DFSR servers with Windows Server 2016 as following :-
IN01 (Primary Sending Member)
US01 (Receiving read only member)

This server IN01 have several errors for replication stopped/failed with event ID 6104, 2004, 2104.

Log Name: DFS Replication
Source: DFSR
Date: 5/7/2021 2:19:46 PM
Event ID: 6104
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: IN01
Description:
The DFS Replication service failed to register the WMI providers. Replication is disabled until the problem is resolved.

Log Name: DFS Replication
Source: DFSR
Date: 5/7/2021 2:15:46 PM
Event ID: 2004
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: IN01
Description:
The DFS Replication service stopped replication on volume E:. This failure can occur because the disk is full, the disk is failing, or a quota limit has been reached. This can also occur if the DFS Replication service encountered errors while attempting to stage files for a replicated folder on this volume.

Additional Information:
Error: 9014 (Database failure)
Volume: B9081C7B-BD6E-4592-B732-C5759621B10D

Log Name: DFS Replication
Source: DFSR
Date: 5/7/2021 2:15:46 PM
Event ID: 2104
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: IN01
Description:
The DFS Replication service failed to recover from an internal database error on volume E:. Replication has been stopped for all replicated folders on this volume.

Additional Information:
Error: 1392 (The file or directory is corrupted and unreadable. (0))
Volume: B9081C7B-BD6E-4592-B732-C5759621B10D
Database: E:\System Volume Information\DFSR

Q1.
I have gone through several articles and web links which states to rebuild/recreate the database as a part of solution but I want to know how to do it and will it cause any data loss?

Q2. If I start the replication again, will it start from zero..? I mean will it replicate all the folders from sending member to receiving member from scratch?

With regards,
Rahul

Answer 1

Hello @RSA111 ,

I am sorry for the late reply.

What exactly you mean backup all the data on IN01?
A: Yes, no matter how large the data on the server is, the data on the two servers had better be backed up in advance to prevent any data loss.

Also when you say "rebuild/recreate replication folders on IN01 (Primary Sending Member)" - Does it mean deleting Replication Group/Replication Folders under DFS Management?
A: Yes, this is what I mean.

And what happens if I delete database folder under System Volume Information?
A: Data may lose.

How exactly I can rebuild the database? The steps?
A: Because in your case, US01 is Receiving read only member, you only need to rebuild/recreate replication folders on IN01 (Primary Sending Member), if you rebuild/recreate the database of IN01 (Primary Sending Member), IN0 can not replicate data from US01 (Receiving read only member).

For rebuilding the database, you can refer to the similar case.
DFSR - Database Corrupt
https://social.technet.microsoft.com/Forums/Azure/en-US/b69839aa-f050-419c-9344-6b7bf067c318/dfsr-database-corrupt?forum=winserverfiles

Hope the information above is helpful.

Should you have any question or concern, please feel free to let us know.

Best Regards,
Daisy Zhou

============================================

If the Answer is helpful, please click "Accept Answer" and upvote it.

Answer 2

Hello @RSA111 ,

Thank you for posting here.

Here are the answers for your references.

Q1. I have gone through several articles and web links which states to rebuild/recreate the database as a part of solution but I want to know how to do it and will it cause any data loss?

A1: We should backup all the data on both Primary Sending Member IN01 and Receiving read only member US01 before we rebuild/recreate the DFSR database.

Q2. If I start the replication again, will it start from zero..? I mean will it replicate all the folders from sending member to receiving member from scratch?

A2: For DFSR database rebuilding/recreation or DFSR replication group rebuilding/recreation, it will not start from zero.
It will replicate the different data from the other DFSR server, if the data has been filled in and is consistent, it will not be copied again.

Here are some suggestions for your issue:

For your issue, because there is internal database error on IN01 (Primary Sending Member) instead of US01 (Receiving read only member), you want to rebuild/recreate the database of IN0, is it right?

If so, if you rebuild/recreate the database of IN01 (Primary Sending Member), IN0 can not replicate data from US01 (Receiving read only member).

So I suggest you can rebuild/recreate replication folders on IN01 (Primary Sending Member), then it will replicate replication folders to US01, if the new folders and new files you create on IN01 have been filled and are consistent on US01, it will not be copied from IN01 to US01again.

Hope the information above is helpful.

Should you have any question or concern, please feel free to let us know.

Best Regards,
Daisy Zhou

============================================

If the Answer is helpful, please click "Accept Answer" and upvote it.