Brass Contributor

Apr 14, 2022

DFS replication issues

Hello everyone, We are running Windows Server 2016 as a Primary Domain Controller. We don't have DFS management tool installed however I'm getting 6002 errors in event viewer. Please advise on h...

Apr 20, 2022

Thanks, Nikita. That helped a great deal and saved a lot of time.

I'll start at the end and work backwards.

You want to run these commands to clean up what is a very broken DFS-R configuration. I'll provide an in-depth explanation after the commands

Remove-ADObject -Identity "CN=45d9316b-1098-408e-a65d-8ce8449f0aaa,CN=DFSR-LocalSettings,CN=UZTASSRV01,OU=Domain Controllers,DC=sm,DC=local" -Recursive -Confirm:$false;
Remove-ADObject -Identity "CN=a7297769-fdcd-4490-ae1c-c80808f44d36,CN=DFSR-LocalSettings,CN=UZTASSRV01,OU=Domain Controllers,DC=sm,DC=local" -Recursive -Confirm:$false;
Remove-ADObject -Identity "CN=DFS,CN=DFSR-GlobalSettings,CN=System,DC=sm,DC=local" -Recursive -Confirm:$false;
Remove-ADObject -Identity "CN=DFS_IT,CN=DFSR-GlobalSettings,CN=System,DC=sm,DC=local" -Recursive -Confirm:$false;
Remove-ADObject -Identity "CN=UZTASSVR02,CN=Topology,CN=Domain System Volume,CN=DFSR-GlobalSettings,CN=System,DC=sm,DC=local" -Recursive -Confirm:$false;

Overview

What the JSON output you provided showed is:

There are no DFS namespaces configured;
The DFS replication group definitions are badly broken in places;
The "built-in" SYSVOL DFS-R definition is fine but contains an orphaned reference to a domain controller no longer in existence (UZTASSVR02);
Three DFS replications groups are defined:
1. DFS;
2. DFS_IT;
3. Domain System Volume.

Approach

There were two options I could have pursued:

Add the missing "MemberReference" values onto the existing "msDFSR-Subscriber" objects; or
Delete the DFS and DFS_IT DFS replication groups.

I have chosen option 2 since:

There is no associated DFS namespace;
The replication groups would only have a single member, which is pointless;
It provides you with the cleanest outcome, since you can always create new DFS namespaces and replication groups if you decide to later on, and you won't have to worry about old, corrupt data lingering around.

Explanation of each command

Line	Comment
1	Removes the orphaned subscription to the "DFS" replication group from UZTASSRV01.
2	Removes the orphaned subscription to the "DFS_IT" replication group from UZTASSRV01.
3	Removes the "DFS" replication group.
4	Removes the "DFS_IT" replication group.
5	Removes the orphaned UZTASSVR02 reference from the "Domain System Volume" replication group.

Once you have removed these objects, it will take DFS-R a little while to recognise the changes.

If you want to hurry the process up, you can do any one of the following:

Restart UZTASSRV01 (since it's the only remaining host); or
Restart the the "DFSR" service on UZTASSRV01; or
Run the following command on UZTASSRV01 (it may not be installed though, which is fine):

dfsdiag pollad

Anyhow, once you've either waited a bit or hurried things up, you should find the Event Viewer errors stop.

Cheers,

Lain

LainRobertson

Silver Contributor

Jun 11, 2022

Zalastar

Okay, so I think you mentioned earlier something about the FRS migration status being okay, which leads me to assume that an FRS to DFS-R migration took place at some point?

There's still things we can do but I'm keen to check some things first, as they're all edging closer to that "point of last resort" concept.

Does the following command return anything?

Get-ADObject -Filter { (cn -ne "File Replication Service") } -SearchBase "CN=File Replication Service,CN=System,$((Get-ADRootDSE).defaultNamingContext)" -SearchScope Subtree | Select-Object -Property objectGUID, objectClass, distinguishedName

Secondly, were you following the process here when you reset DFS-R ealier?

Force synchronization for Distributed File System Replication (DFSR) replicated sysvol replication - Windows Server | Microsoft Docs

Note: It says D2-like, but it's not actually the older BurFlags process.

Cheers,

Lain

Zalastar

Copper Contributor

Jun 11, 2022

LainRobertson

A big thank you for the time you spend here on this thread! I am so happy right now. Not a single error in the Forest. And my Delta sync times are way down now too

Source DSA          largest delta    fails/total %%   error
 BABBAGE                   26m:58s    0 /  10    0
 IOS-SEA-A1                13m:01s    0 /  20    0
 IOSLA-DCFS                08m:24s    0 /  15    0
 OR-VM-1                   07m:06s    0 /  10    0
 PS-BAY-AD1                21m:10s    0 /  10    0
 PS-I-AD1                  23m:23s    0 /  15    0
 PS-I-AD2                  22m:06s    0 /  25    0


Destination DSA     largest delta    fails/total %%   error
 BABBAGE                   21m:14s    0 /   5    0
 IOS-SEA-A1                   :26s    0 /  20    0
 IOSLA-DCFS                13m:02s    0 /  15    0
 OR-VM-1                   03m:01s    0 /  20    0
 PS-BAY-AD1                27m:01s    0 /  15    0
 PS-I-AD1                  22m:08s    0 /  15    0
 PS-I-AD2                  23m:25s    0 /  15    0

I finally understood what you meant about getting rid of the FRS leftovers

PS C:\Users\administrator.IOSDOMAIN> Get-ADObject -Filter { (cn -ne "File Replication Service") } -SearchBase "CN=File Replication Service,CN=System,$((Get-A
DRootDSE).defaultNamingContext)" -SearchScope Subtree | Select-Object -Property objectGUID, objectClass, distinguishedName
PS C:\Users\administrator.IOSDOMAIN>

Zalastar
Copper Contributor
Jun 11, 2022
What is this strange life outside the box you are referring too 😉
LainRobertson
Silver Contributor
Jun 11, 2022
Zalastar

Sorry, I was just out doing the Saturday morning run-around with the family.

Glad it's all sorted!

Cheers,
Lain

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