Replication Failed Due to Schema Incompatibility? 1

[AkutaSame]

Ok, so here's the lead-up to present day:

Windows 2000 domain with roughly 20 computers. 2 Windows 2000 DCs, 4 non-DC servers and the rest are client computers.

I was requested to install an Exchange 2003 server (not my choice, so please don't tell me how horrible it is! ). I had read many well documented sites stating that I had to prepare the domain because of the changes that are made to the domain/forest when a 2003 server is added to the domain. This domain had originally had an Exchange 2000 server running on it however the server had crashed (hardware failure). This was right about the time that I took over for the company taking care of their network.

Well, so I printed out and followed the MS document for adding a Windows SBS 2003 server to the Windows 2000 domain. I went through the OS installation, stopped the SBS installation and promoted the DC manually and then installed Exchange. The 2003 server SEES the others. The other servers SEE the 2003 server.

Ok, so as per the steps of the integration of the new SBS server I went through the process of transferring FSMO roles. All of them would transfer but the schema master. For some reason, the schema master role will NOT transfer from the 2000 DC to the 2003 DC.

After running dcdiag on all of the servers (they were all having DNS/AD replication errors), it was stating that the RPC server was unavailable... Everything pointed to DNS, yet they all resolve the DNS correctly. When I try to force replication, I get the following error:

The following error occured during the attempt to synchronize naming context schema from domain controller [2000 server] to domain controller [2003 server]:
The replication operation could not be completed due to a schema incompatibility.
This operation will not continue.

I'm hoping the solution won't be the inevitable... The only information on the web about this exact error are on the sites that list Windows error codes.

Thanks in advance.

 

[TechyMcSe2k]

http://support.microsoft.com/kb/325379

You need to run adprep /forestprep from the SBS2003 CD on the windows 2000 DC

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Achieving a perception of high intelligence level can only be limited by your manipulation skills of the Google algorithm!

 

[AkutaSame]

The forestprep has already been run though. That was part of the prepatory procedures lined out in the MS KB article (

http://support.microsoft.com/kb/884453).

After starting to have this error, I then was worried about just that (that perhaps I needed to make sure the DCs recognized these changes) and ran forestprep again. It says that the forest had already been modified and didn't need to be run again.

To give you the exact wording, I have rerun and copied the response:

"Forest-wide information has already been updated.
[Status/Consequence]
Adprep did not attempt to rerun this operation."

This is why it makes no sense that the schema doesn't match; however, when I was looking at the new server's event log I noticed that there were some replication errors... Upon digging a bit deeper, it's telling me that there's something wrong with a bunch of Exchange schema items. It's a bit odd that it's doing this; however, I guess the next step is going to be to demote, clear out AD, and promote again.

Any other ideas?

 

[58sniper]

not my choice, so please don't tell me how horrible it is!

It's not horrible. It's a phenomenal product and works great.

What was the AD health before you started this? Me thinks that with a "failed" Exchange server installed in the past, that that certainly should have been cleaned up before attempting to make two different sets of schema changes.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[AkutaSame]

It's not horrible. It's a phenomenal product and works great."

I have no qualms with Exchange myself. I just get tired of hearing "God, Why use Exchange? You could use X, Y, or Z to do the same job," so I prefaced the MS haters with the fact that I had a solution in place. It was indeed not my decision to switch over, but that doesn't mean that I don't value the things that Exchange provides in addition to "just mail."

It's very possible that a failed Exchange install occured before I took over the network. It's also possible that the schema incompatibility is because I am adding a 2003 server to a 2000 domain (which requires a little prep work).

Half of the problems turned out to be the overzealous Windows Firewall preventing RPC traffic (even if port 135 is opened as an exception, which was weird). Once I disabled the Windows firewall (I'm running through a firewall>traffic filter>NAT>mail relay, so I'm not too worried about having it off), it seemed to resolve the RPC errors. Now I'm not getting RPC server unavailable errors; however, there is still the "schema incompatability" error. The only mention of "schema incompatibility" and this error in question ("The replication operation could not be completed due to a schema incompatibility.") is on a Windows Error list that is all over the internet... yet no fixes.

So the next step, I suppose is to try to demote the exchange server again now that the RPC should be fixed, clean up the metadata for THIS server and make sure that there isn't a residual piece of data that was missed from a failed Exchange install and promote the server again hoping that the task goes unhindered.

 

[TechyMcSe2k]

From SystmProg user within Experts-Exchange:

NOTE:
Adprep will create log files in %Systemroot%\system32\debug\adprep\logs directory. If you have run there should be a log created by both the commands.

These two commands add new classes and attrributes that are supported by Windows 2003 for new features. You can open up ADSI.MSI and see the changes made under Naming Context etc. Forestprep creates a new container named:

*CN=Operations,CN=ForestUpdates,CN=Configuration,DC=ForestRootDomain*

The domainprep operation also creates a new container:

*CN=Operations,CN=DomainUpdates,CN=System,DC=DomainName*

but unlike forestprep, domainprep also creates a second container:

*CN=Windows2003Update,CN=DomainUpdates,CN=System,DC=DomainName*

By the way, these are the operations performed by Adprep:

http://support.microsoft.com/kb/309628/

>>>If adprep /forestprep has not been run, is it even possible to execute adprep /domainprep?

That's not possible. Before you run /DomainPrep you must be sure that updates from /ForestPrep have been replicated to all other domain controllers.


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Achieving a perception of high intelligence level can only be limited by your manipulation skills of the Google algorithm!

 

[AkutaSame]

Thank you for the additional information. What I ended up doing was removing both the new Exchange server and the alternate 2k DC as there were some schema issues created when I added the 2k3 server (Even though I had gone through the MS document to prepare the AD for it). This hopefully will remove the incompatibility (because it no longer exists on those systems) and they will get a new copy from the schema master upon joining domain and being promoted.

The only thing I can do is to wait and see.