Exchange 2019 Upgrade to CU2 is pretty straight forward and in this example we will upgrade using the command line.
Before you run the setup, I generally like to do a reboot of the server as the setup will generally fail saying there is a pending reboot. In some cases, you might have to reboot 2 or 3 times depending on what roles were installed or updates.
To start the upgrade, ensure the ISO is mounted and navigate to that drive letter in your elevated command prompt.
Now type in the following command:
- .\Setup.exe /Mode:Upgrade /IAcceptExchangeServerLicenseTerms
Don’t forget to accept the license terms or you will get an error.
In this example, I did not run /PrepareAD before hand but in the setup you will notice it says Organization Preparation.
As you can see above, the setup ran without an glitch, it took about 40 min on my VM which is not bad. Now that your upgrade is complete, you can reboot the server and then login and make sure all is working ok.
Hope it helps.