Greetings! Thanks in advance from a novice sys admin that's learning by living :)
I currently have a single Windows 2003 Std server running Exchange 2003 Ent that I inherited a few years ago. We've got about 270 mailboxes and a database of about 100GB, so nothing crazy. We're depending on email for business critical operations now more than when the system was built and put in place, so I'm working on building a more robust solution using CCR Exchange 2007/Server 2008 Ent clustering. I'm buying the two servers and I've got a 3rd 2003 R2 server that's going to be the File Share Witness (Not an hub transport server but a server in the same domain). I'm wondering when I build the cluster in the OS and start to install Exchange 2007 on both machines how it will effect the live 2003 exchange server and active 2003 domain?
What I'm hoping to do is bring up the cluster and install Exchange 2007 on both, which I think will show as one exchange server when I view it on the exchange 2003 box, then start migrating users a few at a time to the exchange 2007 cluster and eventually shutdown the exchange 2003 box. With the domain running in 2003 native mode with a couple separate 2003 domain controllers, does anyone foresee any terrible issue I could be running into during this process?
I'm hoping to join the two new 2008 ent servers into the domain without breaking anything and then immediately installing exchange 2007 on them and just moving users over. What do you think or what should I be concerned about? Thanks!