Forum Discussion
Floyds_on_Greenwood
Jul 27, 2020Brass Contributor
ADDS trusted forests.domains A. OnPrem EX2013 B.Office 365 into new ADDS and New 0365 Tenant?
Greetings.
We have two company's (each with their own forest and single domain) that have operated in a trusted ADDS forest configuration. Each forest contains their own respective mail system. One has on-premise Exchange 2013. The other ADDS forest has O365 and uses Azure AD Connect to sync on-premise ADDS users to o365. These mail systems are utilizing Galsync (enow) to support cross forest GAL's.
We are not (yet) using o365 SharePoint, one drive, or other 0365 services other than email. *We will later in the new named entity.
We are now going to merge these two environments (ADDS forest(s) / domain(s)) into a new named ADDS entity (forest and domain) - and new o365 tenant. This new named entity will utilize many of the o365 offerings.
I have migrated/merged trusted forests, and Exchange on-premise 2010/2013 systems together via ADMT and mailbox moves. This looks to be a bit more challenging.
Has anyone performed a similar migration/merge? Would they be willing to share how they did it?
Any insight, links, or thoughts are very much appreciated.
I found something similar in this forum on reddit -https://www.reddit.com/r/Office365/comments/93f4oq/cross_forest_office_365_migration/
Thanks in advance,
- KonstantinosPassadisLearn ExpertHello
So you are going to change UPNs , Primary SMTPs etc? right ?If you think of it, the whole process looks like a scary one , but really it is quite straightforward . First things first , AD Sync is your friend and the very tool that is going to keep things in line . Create your new Tenant , and verify the Mail Domains. You will go Hybrid so people will continue to work, and maybe in the end you may Decommission Exchange 2013 right ?- Floyds_on_GreenwoodBrass Contributor
Yes, you are correct. We are going to change UPNs , Primary SMTPs etc and we will decommission Exchange 2013.
Would you recommend something about the process that might help?
Thank you.
- KonstantinosPassadisLearn Expert
HelloFloyds_on_Greenwood
Sorry for the late answer , i was quite engaged. So have you started yet ? One this i would like to point out is to carefully plan your Identities , just make clear which one is which and what aliases are on them
What about your PST files ? Are they holding a lots of GB ? In a similar case we uploaded all Data and made the Import Jobs from 365 Admin.