Demoting a Samba AD DC: Difference between revisions
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DNS Domain Name/Realm: samdom.example.com |
DNS Domain Name/Realm: samdom.example.com |
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NT4 Domain Name: samdom |
NT4 Domain Name: samdom |
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= Demote a still working Domain Controller = |
= Demote a still working Domain Controller = |
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* [[#Verifying_that_nothing_was_left|Verify that nothing was left]]. |
* [[#Verifying_that_nothing_was_left|Verify that nothing was left]]. |
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= Demote a DC that isn't accessable any more= |
= Demote a DC that isn't accessable any more= |
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Follow this section, if your DC is not accessable any more, e. g. by hardware failure and it surely |
Follow this section, if your DC is not accessable any more, e. g. by hardware failure and it surely will never come back into the network. |
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samba-tool currently does not support demote a foreign DC. That's why currently the only way to demote a lost DC is using the Windows tools. '''Sadly demoting e. g. through deleting the DC in ADUC, currently fails. See [https://bugzilla.samba.org/show_bug.cgi?id=10595 Bug report #10595].''' |
samba-tool currently does not support demote a foreign DC. That's why currently the only way to demote a lost DC is using the Windows tools. '''Sadly demoting e. g. through deleting the DC in ADUC, currently fails. See [https://bugzilla.samba.org/show_bug.cgi?id=10595 Bug report #10595].''' |
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Please use at your own risk. |
Please use at your own risk. |
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[http://gallery.technet.microsoft.com/scriptcenter/d31f091f-2642-4ede-9f97-0e1cc4d577f3#content] |
[http://gallery.technet.microsoft.com/scriptcenter/d31f091f-2642-4ede-9f97-0e1cc4d577f3#content] |
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= Verifying that nothing was left = |
= Verifying that nothing was left = |
Revision as of 17:04, 29 February 2016
Introduction
Whenever a Domain Controller needs to be removed from your domain, for what ever reason, you will have to demote it. This HowTo describes different scenarios to demote a Domain Controller.
Server information used in this HowTo
Inside this HowTo, we will be using the following configuration/settings:
Installation directory: /usr/local/samba/ DC to demote: DC2 Different DC remaining in the network: DC1 DNS Domain Name/Realm: samdom.example.com NT4 Domain Name: samdom
Demote a still working Domain Controller
Follow this section, if your DC is accessable and working.
- Log into the DC you want to demote.
- Verify that the DC is not the last one remaining in the domain!
- Make sure, that this DC does not contain any FSMO role:
# samba-tool fsmo show InfrastructureMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com RidAllocationMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com PdcEmulationMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com DomainNamingMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com SchemaMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
- If you are using Samba 4.3.0 and up, the samba tool command will show an extra two FSMO roles:
DomainDnsZonesMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com ForestDnsZonesMasterRole owner: CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
Irrespective of version, there are 7 FSMO roles, see show fsmo roles for how to display all 7 roles on earlier versions.
- If it still contains one or more FSMO roles, transfer them to a different DC.
- Demote the DC:
# samba-tool domain demote -Uadministrator Using DC1.samdom.example.com as partner server for the demotion Password for [SAMDOM\administrator]: Desactivating inbound replication Asking partner server DC1.samdom.example.com to synchronize from us Changing userControl and container Demote successfull
- Shutdown Samba
Demote a DC that isn't accessable any more
Follow this section, if your DC is not accessable any more, e. g. by hardware failure and it surely will never come back into the network.
samba-tool currently does not support demote a foreign DC. That's why currently the only way to demote a lost DC is using the Windows tools. Sadly demoting e. g. through deleting the DC in ADUC, currently fails. See Bug report #10595.
There are suspicion that samba DC with the metadate of the DC that isn't accessible would eat up memory and later trigger oom-killer.
This information was correct Until 4.1.12, and the same problem might kill the 2nd and 3rd DC if you have.
Some people say that they can remove using the script below, but it was fully not tested. Please use at your own risk. [1]
Verifying that nothing was left
The following steps are done on a Windows computer having RSAT installed.
Warning: The following are just cleanup steps, if something was left after a demote! It's not a replacement for the demote process itself!
- Open „Active Directory Users and Computers“
- Go to the container „Domain Controllers“ and verify that the demoted DC was removed. If not, remove the account manually. This would also cleanup metadata. DC removal via ADUC is currently broken. See Bug report #10595.
- Open „Active Directory Sites and Services“
- Check that the demoted DC doesn't exist any more in any site. If an entry is still there, remove it manually.
- Open the „DNS“ console
- Check in all zones, that no entry about the demoted DC is still existing.