Forum Discussion
Exchange Server 2016 / 2019 coexistence CU update
Hi,
We are running Exchange Server 2016 CU19 and Exchange Server 2019 CU14.
We want to install the latest CU for Exchange Server 2016. Can we do this with Exchange Server 2019 CU14 already installed?
Any pitfalls? I am thinking about the AD Schema perhaps.
Any insights welcome!
Greetings Nfs!
6 Replies
Upgrading Exchange Server 2016 to its latest CU with Exchange Server 2019 in co-existence will not cause any trouble. The infra will work flawlessly post upgrade.
As per schema doubt is concerned, Exchange server only causes schema expansion, so if there is any additional attribute gets added post Exchange server 2016 CU23, there will not be any impact in its service.
Note: Ensure to keep Exchange 2016 to its latest CU and SU version and Exchange 2019 to its latest CU and (n-1) SU version.
If you are already using Exchange Server 2019 with CU14 installed, there is no need to take additional action. For Exchange Server 2016, it is recommended to install the latest Cumulative Update (CU). Once the latest CU is installed, ensure that you also install the latest Security Update (SU) to maintain a stable and secure Exchange environment.
Before applying these updates, it is highly advisable to perform the activity in a test environment first. Additionally, follow all precautionary measures, including taking a recent snapshot of your system, to ensure a smooth update process.
CUs are cumulative, so they contain updates from all previous updates, so you can go from CU14 to CU19 in one install. There may be a schema update required, and you can check this by reviewing all the CU's and checking.
Don't forget to install the latest security update after the CU is installed
Thanks for your reply!
Now the AD schema is already on the latest version because of the Exchange server 2019 CU14 which is the latest CU.
When Upgrading Exchange server 2016 from CU19 to CU23 there are AD schema updates listed in the documentation. How will this react when installing the CU23? Will it just skip the AD schema updates because the scheme is already on the version of Exchange 2019 CU14?
Thanks for your reply!
So the AD Schema should already be up to date because of the Exchange server 2019 CU 14 which is the latest CU.
When we want to upgrade the Exchange server 2016 from CU 19 to CU 23, there are AD schema updates required. But I am wondering how this will react because of the schema already on the latest version.
Will it just skip the schema updates?Microsoft don't support two different versions of Exchange in the same organisation for extended periods (only supported while migrating to the new version), so I'd recommend decommissioning the Exchange 2016 servers and building new Exchange 2019 servers.
