Installing a second Exchange Server 2007 in our Domain...First Storage Group exists error...and implementing SCR between the two

Question

I'm currently attempting to add a second Exchange 2007 server to our domain. The idea is to have it setup with SCR at our disaster recovery site so that in case of emergency we have a known good, working Exchange server with most of our data that's ready to go. We currently only have one Exchange server and approximately 200 users.

I installed Windows Server 2008 R2, then installed Exchange SP1. During the install it failed with the Mailbox Role not being added. Afterwards it all looked similar to the current working Exchange server though. I went ahead and attempted to install SP2, which is what our current Exchange server is at. This gave me the error about a previous install not completed. I found several articles online pointing out where the Watermark registry key was and suggestions to delete that to finish the install. I ran the setup from the command prompt the next time and saw the error (I assume the original error and cause for the Mailbox Role not being installed) First Storage Group in Active Directory already exists. Upon another registry inspection I see that I missed the Action entry that was near the Watermark (which they also suggested to remove), so now I've got both of them removed and am wanting to install SP2.

The thing is, I'm hesitant now because of the Active Directory error. I'm assuming I can run this and install a second Exchange server in the same domain with no interference, right? So herein lies my primary question: so as to not interrupt services with our current working server, can I continue with the install? Is the error it's giving OK? Of course it's not going to be able to add that First Storage group, it already exists on the other server... but what do I need to do so that it is a clean install?

Any help on how best to proceed is greatly appreciated. My end goal is simply to have a backup server running Exchange 2007 just like our current, running SCR so that our data is being backed up offsite and can with minimal effort be turned into our primary server should a disaster occur.

Answer 1

Quite frankly I'm surprised that you tried to install a Service Pack when you know the original install failed. That's almost certainly setting you up for something bad to happen. I'm also surprised you went registry hacking instead of trying to diagnose the actual fault. Error messages are there to tell you something is wrong, and you don't just blindly ignore them or hack the registry to make them go away and pretend like nothing is wrong.

Anyway, the Exchange installer gives pretty clear reasons why things fail and it also creates a detailed setup log. The full error message you get and some excerpts from the setup log would be very helpful in diagnosing the problem, and if you edit your question with these details, we may be able to help more.

If I were you, what I'd be doing right now is trying to fix the first problem you came across with the mailbox role not installing. The Exchange best practices analyser might tell you what is wrong, but you might also end up having to start over. Deleting those watermark registry keys might have actually destroyed any chance you have of fixing this server, and if so I'd be going to completely uninstall Exchange from the control panel. It's important you properly uninstall using the control panel because this will update Active Directory and properly remove this server as an Exchange server (you'll have more problems later on if you don't do this). Whether you wipe the server or simply try to re-install Exchange again afterwards is your choice (personally I'd format the server). Just make sure that when you run Get-ExchangeServer on your other Exchange server that there is only one and the failed installation is not listed.

Ordinarily, yes you can install Exchange on multiple member servers with no issues or conflicts. When you have errors with your installation process however, I wouldn't proceed any further until the errors are resolved. Exchange shouldn't let you do something silly like overwrite something that already exists, but the fact it even tried makes me nervous you might have something else wrong.