exchange 2003 to 2010 upgrade with multiple sites

[evinfo]

All -

we are in the process of migrating our current 8.0.4 EV with Exchange 2003 to EV 9.0.1 Exch 2010. We want to also upgrade the hardware from Windows 2003 to Windows 2008 R2.

Currently we have the following setup:

US site - Europe Site - Asia site -> All three distinct sites with their own directory database.

Future -

US site - Europe site - Asia site -> We want to keep all 3 sites but bring them under one directory database.

I have a certain idea but I wanted to see if anyone can shed a light on best practices.

thank you very much.

[JesusWept3]

You cannot merge seperate Directories in to one directory, you would have to go through and add new sites to the directory database that you wish then migrate all the users across, other than that, you'd have to use seperate sql servers or seperate sql instances, and honestly, depending on the link quality between your APAC, EMEA and Americas sites, you'd be best of having the Directory as close to that region as possible.

Other than that, would suggest upgrading EV to your target version first on the old hardware, then do a reinstall per the DR procedures in the Administration Guide to have it set up on the new servers

[evinfo]

Thanks for the info. We have a very good link between all sites.

Option1:

Leave all three sites as is and perform upgrade to EV 9.0.1 on old hardware and perform DR procedure reinstall to the new hardware. Keep the 3 sites with their complete own directory db, etc.. (as is today)... Once we have the new exchange 2010 servers, we would add the tasks to archive those servers and begin to migrate the users from 2003 to 2010?

Option2:

So, if I wanted all three sites to reside under the one directory db in US, I would have to create the EMEA and APAC site under the US directory db and migrate the users from EMEA and APAC using "Move archive" or third-party tool. Thereafter (as above) perform the 2003 to 2010 migration.

If this was a fresh install then Option2 would not be an issue as we would not have to move the archives of the users?

[JesusWept3 · Accepted solution]

Yup, Option 2 from scratch would be easy enough, but merging three established environments in to one? that would be unfathomably painful for you

[evinfo]

You are an excellent source to bounce ideas off of.. very much appreciated it..