[Samba] ERROR: missing backlink attribute 'memberOf'

Andrew Bartlett
Wed, 06 Dec 2017 17:54:49 -0000

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