Need urgent help with samba4 DC re-join

Andreas Oster aoster at novanetwork.de
Thu Jun 28 07:16:22 MDT 2012


Am 28.06.2012 09:20, schrieb Andrew Bartlett:
> On Thu, 2012-06-28 at 07:26 +0200, Andreas Oster wrote:
>> Am 28.06.2012 00:00, schrieb Andrew Bartlett:
>>> On Wed, 2012-06-27 at 19:27 +0200, Andreas Oster wrote:
>>>> Am 27.06.2012 15:43, schrieb Andreas Oster:
>>>>> Am 27.06.2012 15:35, schrieb Andrew Bartlett:
>>>>>> On Wed, 2012-06-27 at 15:28 +0200, Andreas Oster wrote:
>>>>>>> Am 27.06.2012 15:21, schrieb Andrew Bartlett:
>>>>>>>> On Wed, 2012-06-27 at 15:09 +0200, Andreas Oster wrote:
>>>>>>>>> Hello Andrew,
>>>>>>>>>
>>>>>>>>> i think the only differences when doing a "ldbsearch -H sam.ldb -s base
>>>>>>>>> -b DC=DomainDnsZones,DC=novanetwork,DC=loc" are:
>>>>>>>>>
>>>>>>>>> objectClass: domain
>>>>>>>>> objectClass: domainDNS
>>>>>>>>>
>>>>>>>>> and
>>>>>>>>>
>>>>>>>>> objectCategory: CN=Top,CN=Schema,CN=Configuration,DC=novanetwork,DC=loc
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I do not know if this was correct before demoting the second DC.
>>>>>>>>> It did not come into my mind to check for errors because everything
>>>>>>>>> worked like a charm and I was/am really happy with samba4.
>>>>>>>>>
>>>>>>>>> here the output of:
>>>>>>>>>
>>>>>>>>> ../bin/ldbsearch -H sam.ldb -s base -b
>>>>>>>>> dc=domaindnszones,DC=novanetwork,DC=loc --reveal --show-binary
>>>>>>>>> replPropertyMetaData
>>>>>>>>
>>>>>>>> Thanks.  This gives us a very good clue as to what has gone on:
>>>>>>>>
>>>>>>>> I'm assuming that 61f36cfd-ba7d-4702-87d3-7e861bb32cfe is PDC and
>>>>>>>> fd9ca123-ed33-483a-a735-ff41940789a2 was the BDC?
>>>>>>>>
>>>>>>>> The key attributes changed that you mention are objectClass and
>>>>>>>> objectCategory.  Both need to be fixed.  The incorrect values seem to
>>>>>>>> have been written at Sun Apr 22 16:07:06 2012 CEST compared with Sun Apr
>>>>>>>> 22 16:03:41 2012 CEST for the good ones.
>>>>>>>>
>>>>>>>> My guess is that in attempting to replicate the DNS to the slave with
>>>>>>>> the samba-tool drs commands, and running samba_upgradedns on that
>>>>>>>> server, have somehow sent back a corrupted version of the same object.
>>>>>>>>
>>>>>>>> Andrew Bartlett
>>>>>>>>
>>>>>>
>>>>>>> Hello Andrew,
>>>>>>>
>>>>>>> this is absolute possible. In a prior try to replicate the
>>>>>>> DomainDnsZones and ForestDnsZones I used the samba-tool drs command but
>>>>>>> this did not succeed and, if I do remember correct, quit with an error
>>>>>>> message. As everything kept on working as before, it did not come to my
>>>>>>> mind that it might have broken anything.
>>>>>>>
>>>>>>> Do you have an idea how to fix this ?
>>>>>>
>>>>>> ldbedit -H sam.ldb -s base -b dc=domaindnszones,DC=novanetwork,DC=loc
>>>>>>
>>>>>> Then set:
>>>>>>
>>>>>> objectClass: domainDNS 
>>>>>> objectCategory:
>>>>>> CN=Domain-DNS,CN=Schema,CN=Configuration,DC=novanetwork,DC=loc
>>>>>>
>>>>>> That should fix it (I hope).
>>>>>>
>>>>>> This is the end for me for tonight, but I'll follow up tomorrow.
>>>>>> Hopefully others here can help you with any remaining details. 
>>>>>>
>>>>>> KEEP GOOD BACKUPS.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Andrew Bartlett
>>>>>>
>>>>> Hello Andrew,
>>>>>
>>>>> thank you very much for your help. I appreciate very much that you use
>>>>> your limited time to help guys like me.
>>>>>
>>>>> I will create a backup and do the proposed changes with ldbedit. I will
>>>>> report here if joining works again afterwards.
>>>>>
>>>>> best regards
>>>>>
>>>>> Andreas
>>>>>
>>>>>
>>>> Hello Andrew,
>>>>
>>>> unfortunately, I have been unable to modify/add the settings via
>>>> ldbedit. I got the following error message when committing the
>>>> modifications:
>>>>
>>>> ../bin/ldbedit -H sam.ldb -s base -b dc=domaindnszones,DC=novanetwork,DC=loc
>>>> failed to modify DC=DomainDnsZones,DC=novanetwork,DC=loc - cannot change
>>>> replicated attribute on partial replica at
>>>> ../source4/dsdb/samdb/ldb_modules/repl_meta_data.c:1408
>>>>
>>>> Any idea what could be causing it ?
>>>
>>> When Amitay first wrote samba_dnsupgrade, he misunderstood about the
>>> difference between a partial and a full replica.  A partition does not
>>> start as one, and then become another.  We will need to correct your
>>> database to record the DNS partition as being a full replica. 
>>>
>>>> Luckily, I did a vmware snapshot before demoting the second DC, I was so
>>>> upset that I forget about that. I have now reverted back to the old
>>>> snapshots and second DC is functional again.
>>>> I have done the tests with ldbsearch on the DomainDnsZones and
>>>> ForestDnsZones and realized, that the faulty entries already existed
>>>> before demoting. So I guess before I can demote the second DC again I
>>>> will have to fix those errors.
>>>
>>> It will also be required before any modifications can be made.  This may
>>> explain why DNS entries appear to be 'stuck' - Samba is refusing to
>>> change anything in that partition, because it wrongly believes that
>>> someone else is the master for that data. 
>>>
>>> Andrew Bartlett
>>>
>> Hello Andrew,
>>
>> do you have an idea what needs to be changed ? Is it only the
>> DomainDnsZones and ForestDnsZones part or are there other places where
>> changes need to be made ? Yesterday I have tried to change the
>> DomainDnsZones stuff but got an error message when trying to commit the
>> modifications.
> 
> That is what I was trying to explain.  The fact that the NTDS Settings
> for your DC lists these as partialReplica partitions is the cause of the
> problem. 
> 
> We need to correct that in your instance, and if we find that many folks
> have run the buggy version of the samba_dnsupgrade script, we may need
> to add a special case to dbcheck for this.  I'm already thinking a
> schema compliance check would be very worthwhile, so this can be found
> before modifications are made.
> 
> Andrew Bartlett
> 
Hello Andrew,

so, how should I proceed on from here ? What can I do to fix those issues ?

best regards

Andreas



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