Office 365 - Going full cloud and removing the hybrid environment

[rich_tech]

Hello all,

 

I am about to embark on the final stages of this migration and unhook our remote hosted exchange 2010 box from our setup, are there any pitfalls I need to look into before doing this ? I have read the MS document about it, but it doesnt 100% make it clear about going full cloud, is there anything further I need to consider before pulling the chain ?

[Steve21]

Do you have ADFS or something in place for Single Sign-On? Unless they're all logging in again etc Are all MX/autodiscover etc records pointing to the new place?

 

Steve

[mikkydoos]

Hybrid borked my DC badly. Super big backup 1st

[rich_tech]

There is an adfs server in place, I have changed all the auto discover / mx records over on all domains (there were over 15 in our group that was fun)

 

How did it break your dc if you don't mind me asking?

[2ilent8cho]

I am in the same boat, but decided against it after reading this https://blogs.technet.microsoft.com/exchange/2012/12/05/decommissioning-your-exchange-2010-servers-in-a-hybrid-deployment/ as we still use onsite AD and Sync it to Office 365.

[apearce]

When you say remove hybrid what exactly do you mean? When I read this I'm assuming you mean just exchange rather than authentication, would that be correct?

 

If its just Exchange Hybrid, you need to ensure all DNS records are pointing to Office 365 (autodiscover, ms, txt etc). After you have done this you should look to remove the send connectors in the ECP in O365, this will remove the need for mail to be sent back to your exchange server and of course this is not what you want if your exchange server has been removed.

 

The best way to decommission an exchange server is to unisntall it, you will need to ensure that all mailboxes are removed and the uninstall process will tell you if it finds any. Once it is removed you are fine.

 

If you are looking to remove AD Connect/ADFS, this is a bigger story because of the way Exchange extends the schema in AD for mailbox attributes. When you implement a hybrid exchange and move mailboxes around it updates the local attributes of the users mailbox according to what is in 365. If you want to keep this in place or if you do need to remove AD COnnect (for some reason that I can't think of yet) I would look to be removing the extended schema for exchange in AD. If you don't this could cause a mismatch and errors to users as to where AD/Outlook thinks its mailboxes are located.

 

Im summary, remove Exchange, dont remove AD Connect

 

I'm also assuming you dont mean sharepoint hybrid ;-)

[rich_tech]

I am in the same boat, but decided against it after reading this https://blogs.technet.microsoft.com/exchange/2012/12/05/decommissioning-your-exchange-2010-servers-in-a-hybrid-deployment/ as we still use onsite AD and Sync it to Office 365.

 

I read the same article, the only thing is with our environment, its a hosted exchange server and we want to get rid of the hosting costs here, which is why I was wondering about the pitfalls people have experienced, I don't fancy a DC going bang on me,

 

So far I have :-

Migrated Mailboxes

Sorted Device Relay out

Changed DNS/MX records to point to cloud domains

 

I am at the "unhook the exchange server bit" now and weary that it will have knock on effects. (Remove the exchange server from proceedings)

 

Our ADFS solution is staying and in-situ at the moment, its not likely to go anywhere either.

[mikkydoos]

How did it break your dc if you don't mind me asking?

 

I still don't know tbh. Something must have gone badly wrong with the inward coming sync. Had to completely rebuild my primary DC. Luckily I managed to get to my 2nd one before it borked too.

 

 

EDIT: We weren't running exchange. It was a hybrid deployment of Office 365 that wrote back O365 changes to you DC.

Edited November 24, 2016 by mikkydoos

[apearce]

So far I have :-

Migrated Mailboxes

Sorted Device Relay out

Changed DNS/MX records to point to cloud domains

 

You should also look to ensure you have an SMTP relay setup and all your devices are removed from your current exchange and now looking at a different SMTP. before we move the hybrid we shutdown the server for a few days to find if we have missed any and change those and then look to uninstall it.

[rich_tech]

You should also look to ensure you have an SMTP relay setup and all your devices are removed from your current exchange and now looking at a different SMTP. before we move the hybrid we shutdown the server for a few days to find if we have missed any and change those and then look to uninstall it.

Sorry, to clarify - Device Relay - I meant SMTP relay, thats in place and firing out fine here on O365 now

 

I have a feeling we may try a remote shutdown and leave it off to see if any issues raise, we have already had to look at things like ADSI edit and proxyaddress adding in for users, but it does seem to be working setting users up online with it so far.

 

Thanks,

[AlanD]

If you are running your exchange in hybrid mode - then its NOT possible to do away with your on-site Exchange and retain any sensible way of managing your email. Its one of the downsides (possibly the only one) of running exchange in hybrid mode. The normal and supported way is to migrate your users to the cloud - then turn off your local exchange. Once you switch on hybrid mode - there is no way to switch it off and revert. And Microsoft will charge you for what is effectively going to be setting up a new tenancy (yes - with the same name as you have now) to get exchange working with Office 365 in the cloud. Pf course keeping your exchange box on site - even if it holds no users - will solve your problem of providing an on site relay for emails (from devices like printers, etc)

[rich_tech]

I just saw the update to this today, I wanted to follow up on this and the help I received, this project is now closed off by me in work. I am not 100% here that it was configured as a true hybrid environment looking at the setup and how it is behaving now in relation to the MS stuff I read.

 

I have actually removed the exchange server from the mix for the last three weeks, it hasn't been to any noticed detriment so far, I noticed now that we can pretty much manage everything from Exchange Online, it doesn't give the synced with AD error messages as before to make changes on the exchange management console, its now making the changes live on the web which it didn't before.

 

We really had no choice here with its removal as our "on-premises" exchange was actually hosted in a data centre by a third party and we were paying that company a monthly cost for each of the mailboxes on top of the additional storage and hosting costs of the server. I think I have saved my company in the region of £30,000 a year in costs for the removal of the solution.

 

I know that if there are any issues, we can actually setup a local exchange according to Office365 as they support a local copy of the server which doesn't host any mailboxes, though if we needed to fire that up now, it would be local to our site this time around.

Edited December 28, 2016 by rich_tech