I thought that errors while updating Hyper-V Integration Services were thing of a past, but Microsoft Updates from January and February 2018 are proving me wrong https://www.informaticar.net/windows-server-2012-r2-with-exchange-failing-kb4072650-and-kb-4057903/. The problem is, you update Hyper-V Integration Services on Windows Server 2012 R2 with Exchange install on it and it freezes.
In my experience it does not happen on every installation, one member of an Exchange DAG would pass update normally, while other one would fail, and both have exact same configuration, so the problem is quite unusual.
So, in case anybody experience this in the future, here is the solution.
You installed Hyper-V Integration Services update and server is asking for a reboot. You reboot it, and then are greeted with the following message
And it just spins for tens of minutes. If you are lucky as I was recently you’ll finally see desktop after half an hour of spinning circles, and give it another half an hour and it will revert update and reboot itself. If you are lucky.
If you are not lucky, this is the only screen you’ll get. If you don’t have cluster for your Exchange you probably don’t have hours to resolve this issue.
So, if you see screen above and your Exchange is not booting, do as follows.
Insert Windows Server 2012 R2 installation ISO or DVD and boot VM from it.
Select Repair your computer
Select Troubleshoot
Select Command Prompt
CMD should open with Admin priviledges, you should navigate it to C:\Windows\System32
and enter following commands
bcdedit /set {bootmgr} displaybootmenu yes
bcdedit /set {bootmgr} timeout 30
Reboot server, and let it boot from the boot drive
On this screen hit F8 on your keyboard.
Choose Safe Mode
You should be able to boot to the Safe Mode. After you get to the Safe Mode head to Control Panel | Administrative Tools | Services
Find Exchange Services and disable them all
If you want to automate process, look here for bulk Disable/Enable of Exchange Services – https://www.informaticar.net/how-to-enable-or-disable-exchange-2013-services/
Reboot the server, it should now boot normally. Update Hyper-V Integration Services (Exchange Services still disabled), reboot server and then re-enable Exchange Services.
That should be it, situation resolved.