[Samba] ERROR: missing backlink attribute 'memberOf'

[Andrew Bartlett]

On Wed, 2017-12-06 at 10:16 -0500, Bob Thomas via samba wrote:
> Good Morning (or not),
> 
> I am running three Samba AD DCs all at version 4.7.2 on Ubuntu 16.04.  
> All three have run flawlessly for over a year.
> Last night one of the DCs started failing Replication with both the 
> other DCs so I decided to run samba-tool dbcheck .
> Resulting in several:
> 
> ERROR: orphaned backlink attribute 'memberOf' in CN=Annamarie 
> Foyles,CN=Users,DC=cy,DC=cybernetics,DC=com for link member in CN=CY 
> Folder Redirect (Win 7),CN=Users,DC=cy,DC=cybernetics,DC=com
> Not removing orphaned backlink memberOf
> 
> ERROR: orphaned backlink attribute 'memberOf' in CN=Darran T. 
> Price,CN=Users,DC=cy,DC=cybernetics,DC=com for link member in CN=CY 
> Folder Redirect (Win 7),CN=Users,DC=cy,DC=cybernetics,DC=com
> Not removing orphaned backlink memberOf
> 
> So I ran samba-tool dbcheck --fix which fixed a few of them and actually 
> got the replications working again, But there are several of those same 
> errors on all three DCs.  I have searched the list and see that the 
> cause of the Backlink removal error has been fixed in version 4.7.1 but 
> the db needs to be cleaned manually.  Just to let you know,  samba-tool 
> dbcheck --cross-ncs passed with no errors following the upgrade to 
> 4.7.0, 4.7.1 and 4.7.2 so i'm not sure how the errors are here now.
> 
> MY QUESTION IS: Could anyone provide me with the directions I need to 
> use to safely manually remove the troubled orphaned backlink attributes 
> so the DCs are happy again.  At the moment everything is working fine, I 
> just need to get the db healthy.

As long as replication is going again, don't worry too much.  An
improved dbcheck will be in the next 4.7 release but otherwise I
wouldn't worry too much.

I hope this helps,

Andrew Bartlett
-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba