Restoring all domain controllers in a Windows domain (on vmware)

Recently I restored a single AD on my homelab without any problems.

However, it was not a production environment like yours.

Take a look on this article:

https://www.veeam.com/blog/active-directory-domain-controller-backup-recovery.html

Those articles look great for restoring a single object - but I might have to restore the entire AD database (for reasons too deep to go into here).  I wonder if I just restore the entire vm image?

Also, I have another potential problem: one of the 3 DCs did not have application aware processing turned on so it does not even show up in the restore wizard - turning that on tonight!  I think there was initially problems with that DC and somehow then it never got fixed or at least turned on.

Albert

I had to do it once; after a ransomware hit.

we restored the backup of the primary dc, it was only 12 hours before (old) backup, but we faced some issues in trust and Kerberos authentication, but just making the gpupdate / force in most pcs with the problem it was fine, just one of them (they were 200 clients) needed to be kicked out of the domain and adopted back in.

after restoration ok, we deployed a new secondary domain controller, not restoring the backup, to avoid authoritative or sync issues.

hopefully helps you.

cheers.

Morning!

Veeam would be terrible backup software if you couldn’t recover your AD environment, so the answer is a definite YES!

Lets go over a few basic parts to this and build a strategy for you:

Firstly, you’ve quite rightly highlighted your DNS will be impacted. We need to consider the impact from a few perspectives:

• vSphere: Does vCenter manage the ESXi hosts via FQDN entries or IP addresses? If it’s via FQDN, you’ll be best avoiding using vCenter within Veeam for your recovery as you’d have to mess with your VCSA to avoid the DNS issues. We can just target an ESXi host via IP address within Veeam
• Veeam: Veeam needs to be able to talk to its components, is your Veeam server an “all in one” box? If not, are your components/servers being targeted via FQDN or DNS? If FQDN I would just edit the hosts file to ensure this continues to work.
• AD: What DNS configuration are you using here? Are all the domain controllers aiming at themselves (relying on DNS replication) within their DNS client/network config, are they all pointing to a central DNS server, or are they all aiming at each other. This could impact how you want to recover.

Secondly, what OS are your domain controllers? Windows Server 2012 R2 added some virtualisation safeguards for AD to help if you restored a DC out of sequence.

Thirdly, check your retention policy, make sure the backups you’ll need aren’t going to be deleted due to retention this week, if in doubt you could also export the backups you need for an extra layer of confidence.
 

Finally, are your DCs backed up at the same time or at different times? I’d want to use the latest backup available as my primary and reattach my older DC backups to that.

Once we’ve got some information here to play with, we can put together a more tailored plan.

I’d also suggest using virtual labs to test this in an isolated network prior to carrying out in production, so you can be confident you’ve hit any & all snags prior to doing it “for real”, and as you can do this with the same backups you’ll actually want to recover from (as you said you could be going back a few weeks), so it will be an identical process.

I did this recently mid day in a HUGE environment after someone blew it up. 100’s of VM’s and file servers were not accessible and critical infrastructure was all down.(stressful)

1. YES make hosts files. Have EVERY Veeam server or other server you will need in it, Proxies, storage, Veeam server, SQL server, ESXI host, vCenter, file shares etc. I now have an updated copy in multiple spots if it happens again. Also keep a list of all your Veeam IP’s on hand so if you ever lose DNS.
2. Consider separating your DC’s and DNS servers. They don’t need to stay together. this makes life much easier going forward.  (Still keep a host file available if you need it)
3. Call Veeam support for help if you need. 

4. The easiest way for me would be to power down ALL of the DC’s and restore the master as authoritative. I’d then restore the other/rest and let them sync. Having the roles on on DC going forward lets you know that that is your master and you should always use it for restores. 
5. There is a procedure for this, Call Veeam and see what they say if your app aware processing doesn’t work.  You will be ok, but i don’t know if the procedure changes. 

In a smaller environment (35 workstations), with not a lot of new activity, what causes a trust relationship to get lost - are they renewed every few days or something?  Or would the only ones lost be those of any new PCs added to the domain?

hopefully Veeam support is faster than the usual response - but maybe if this is severity 1 I will get someone right away - going to try this on a long weekend starting Friday

-so in short, I power down all 3 DCs, restore the one which I think has the best data, issue a command at the command line or a registry setting to make this the authoratative server, then restore the other 2 servers right?

Scott wrote:

3. Call Veeeam support for help if you need
4. The easiest way for me would be to power down ALL of the DC’s and restore the master as authoritative. I’d then restore the other/rest and let them sync.

You have to log into the machine with a local password.  You MIGHT be able to log into the machine with a cached domain password if the machine is disconnected from the network.  Then connect to the network so that it can contact the DC.  It then authenticates to the DC with your admin credentials and creates and syncs a new machine password with AD.  The Netdom and Reset-ComputerMachinePassword PowerShell cmdlet performs the same basic functions here.  Once both the workstation and AD are in sync with the passwork, the trust relationship is validated.  I’m not sure where the password is generated...I’ve always assumed that the workstation generates the password and tell’s AD what it is using your AD creds. 

Note that this is going to be for member servers and workstations.  DC’s don’t have a local admin password and should always be able to communicate with the copy of AD it’s hosting on itself.  If a DC becomes disconnected from the rest of AD due to sync issues (firewall, VPN, etc), and it’s been too long, it can become tombstoned and can no longer safely synch with AD. 

As for your command syntax, you can type in the /pd:bigFatPassword if you need to script things.  That said, to type it realtime (prompted) remove the bigFatPassword and replace it with *.  Using /pd:* will prompt you for the password so that you don’t have a domain admin password sitting on a script or note or whatever somewhere.  I don’t believe you have to use the /s:DC1 to specify a server name…..omitting it should cause it to connect to any DC it can talk to.

I’ve never reset a DSRM password….I imagine it can be done but I’ve never checked.  Of course, if that was the case, I assume you’d need to have valid domain access to the DC to do so.

Really nice topic which mix Veeam and AD knowledge. By luck I never had to restore all DCs of the infrastructure. But I ll keep all this precious advices in a corner. 

I have thought of that too - just restoring one DC, cleaning it up and then building others from that.  The DC with most likely the latest changes on it (password changes, trust relationships) though does not hold the FSMO roles.  So if I started with this, I would have to seize all the FSMO roles.

If I start with the server with the FSMO roles, it is at their head office but because most of their users log into VDI desktops at their data center, most likely there will be more broken trust relationships.

Anyhow, hopefully it does not come to this.  Here is my plan (for what it’s worth); I started this thread to get an understanding about recovering via Veeam backups but I am actually just going to try to get AD working again across sites.  As a reminder, the problem is there was a new DC being built that has become corrupted (not accessible) and the computer object in AD looks “messed up”.  No way to get into the DC to demote it and clean up.  But it is running and if I down it, one of our servers stops working.  I won’t go into more details but suffice to say, I need to get that DC out of the domain, clean up AD and then promote a new one.  So here is my plan that if all goes well, there will be no restore from backup:

• down the problem DC
• delete all the references to it in AD manually
• AD synching seems to be somewhat stopped - repadmin says the DCs can connect but replication stopped due to errors
• issue commands to “force” replication between the good DCs
• hopefully all is well

Question: having said the above, if I just do the above, will the bad DC object just come back from one of the other DCs?  Do I need to delete it on all DCs manually before forcing the replication?  or should I maybe down all DCs except one, make the deletion, set that DC as authoratative (via the registry setting I have read about), reboot that DC (I assume I need a reboot for the setting to take affect) and then bring up the other 2 DCs and force a replicate?  comments?

The restore of all 4 of our DC’s  by useing one as authoritative, then restoring the other 3 went super smooth when we used  Veeam support to assist us.

The things that took the longest were about 2 hours fixing DNS problems we had. Granted our DC’s had a crazy issue and all crashed. Now DNS is separate, but those host files would have been nice BEFORE hand.  Get your DNS working before and you are already ahead of the game for DR planning.

The restore took longer than expected for us as well. I can’t remember if it was something with networking, storage, or VMware but it took about an hour to restore the DC and I was expecting minutes. 

All in all it went great.  You also have the benefit of powering them all down, doing a snapshot or backup BEFORE you start while everything is in a consistent state so it’s pretty stress free.

Deleting the DC’s from AD will not remove their DNS entries as I recall.  You’ll likely need to manually delete those entries from DNS.  You should be able to do this from any DC that is replicating properly.  Once those changes have replicated, you shouldn’t see any more entries for those old DC’s.  That said, you’ll need to remove them from Active Directory Sites and Services to actually remove the DC’s from AD and again, those changes would be replicated to other valid DC’s in the domain.  A graceful demotion is always better than forcibly removing DC’s from a domain, but over the course of this conversation, it sounds as if that’s not an option.

I believe if you forcibly remove a DC from a domain, there will be several DNS records remaining, such as the parent record, A record, and if there are any other records that reference the removed DC, those as well.