Exchange 2010 to Exchange 2019 Migration

[Costas_Psaltis]

Old installation getting around to upgrading. Here are my problems\thoughts?

Current environment is: Single 2008R2 server, AD, Exch 2010.

Moving to Server 2019 vm's. Have a 2019 guest as a DC but forest level still 2008 R2. Exch 2019 requires level to be 2012+.

So, after I move the file share and SQL to their own guests (everything on single physical machine currently) plan is to demote current "server2". Exchange likely will complain about no DC but then add as member of the 2019 guest DC. Then bump the forest level to 2012? Then install Exch 2019 to its own guest. Then move the mailboxes from the 2010 store to the 2019 store. Remove and uninstall Exch 2010. Then possibly bump the forest level to current?

Thoughts\issues: Will Exch 2010 behave correctly while demoting "server2" and then adding the machine to the domain? Is it possible to go directly to Exch 2019 from Exch 2010 or do I have to create an Exch 2016 as an interim step? I would really hate to export all the mailboxes, remove Exch 2010, bump the forest, install Exch 2019, and import the mailboxes.

Thanks in advance,

[#2]

For your process you can't move directly from Exch 2010 to Exch 2019.
You need to add DC with the compatibility matrix of Exchange 2010 like Windows 2016.

https://docs.microsoft.com/en-us/exchange/plan-and-deploy/supportability-matrix?view=exchserver-2019...

After you can add Exchange 2016 server. Move the mailboxes on it. When is done remove the old DC then add Windows 2019 DC and Exchange 2019 server. Move the data from Exchange 2016 to 2019. When is completed remove the temporary Windows 2016 DC.

[#3]

@Thierry - Yes, found that out. So far what I've tested is the following.

Removed AD from existing 2008R2. Made existing "server2" a member. Promoted domain & forest to 2016. Still connects to OWA.

Created Server 2016 guest, applied .NET 4.8 & UCM & C++ req's as stated when attempted to install Exch2019. Exch2016 required kb3206632 as well. In the process of installing Exch2016CU21 right now to test mailbox migration.

[#4]

Good job !
Everything look good
Let me know 😊

[#5]

So far so good migrating mailboxes. The only thing I forgot was to bump the mailbox limit so got some sync errors moving some mailboxes.

There is the next step, moving from Exch2016 to Exch2019. 🙂