Forum Discussion
Remove On Premises exchange Hybrid and go fully Online
Hi Keith,
Been through the comments in your thread and reminded me of my previous project where the customer stated to go fully online after moving the last mailbox to the cloud since they were using a hosted mailbox solution and had to continue paying if they wanted the hybrid to remain.
We did the following
1. Remove the hybrid relationship between the hosted exchange and the Office 365
2. Change DNS records to fully go O365 based ( autodiscover, SPF, DKIM, MX )
3. Update the AAD connect to only use the the current primary AD Forest for sync.
The customer's team had no issues in updating required attributes using AD. But Microsoft FastTrack came back stating that if we do the O365 with only an AAD Connect in place and no exchange server then it puts us in an Un-Supported platform when you call Microsoft for any help.
What they suggested is that you need to have Exchange installed atleast to make sure that your Schema supports the right attributes and that the exchange server should be used to provision the mail enabled accounts so that the right attributes are synced to the cloud.
I do have an email from FTC, but unfortunately cannot share it in public as the information contains customer sensitive information in it.
To end the story with that customer, we ended up installing a minimal exchange server and back to hybrid configuration to make sure that the configuration is still supported.
Not sure what you would gain by removing that exchange server unless its a high dependency on some resources, costs etc, i would suggest to leave the hybrid ON. It can also be used as an email relay within the organization. You can trim down the hardware and give just the bare necessary requirements in it.
Hope my previous situation and its outcome helps you.
Regards,
Prashant
Gentlemen,
Thank you for this valuable info first of all. Secondly, I am with the school of thought that you can keep managing attributes in AD especially the mail ones like proxyAddress and targetAddress attributes. Having your last Exchange server around is unnecessary to me personally as the simple process of create accounts and syncing attributes is simple enough to provision mailboxes in Exch Online.
However, I can assume why Microsoft has given us a blanket answer for keeping ONE last Exch server around. The answer being that while MS goes around updating exchange server versions behind the scenes for all the client tenants. They may introduce new attributes (perhaps?) that only Active Directory may not house. I am talking about msExch attributes which is a big deal. Having a gap say between customers decommissioning from an Exchange 2013 hybrid while Exch Online will be running 2019 for a customer tenant. This is a dangerous gap to have... wouldn't you all agree? With having one exch server around, the onus will be on the customer to eventually upgrade the AD schema and employ such newer attributes to take advantage of features in Exch online. I hope I make sense in my assumption. What are your thoughts?
Everything you say makes sense, but it all comes down to running an environment supported by Microsoft. This may or may not matter in some scenarios but for me anyway I'd rather be managing a supported setup.
I'd highly recommend having a look for Hybrid related sessions coming out of Ignite 2018 as the story may have changed somewhat.
Ian
I am just now looking into doing a O365 migration and when you look at the MS documentation they really push the Hybrid path for any site over 150 users, but it doesn't talk in the migration planing guides about the issues with decommissioning. Only because I am doing a lab setup and I am getting to the decommissioning faze with that, that I running across this.
It seems like if this is the migration scenario they are going to push they need to do some more work on getting it so you can really do a clean cut at the end.
