Hello,
Small business, about 35 computers.
Single domain, no Windows servers, only 2 Zentyal controllers on 5.1.3
Main domain controller is a dedicated physical server, additional domain controller is a virtual machine.
I was wondering if I can update the additional controller first, and if there's any special procedure.
The idea is that if anything goes wrong I can simply reinstall the VM, and if the upgrade works smoothly I can proceed to updating the main controller.