I’ve recently created a two node vSphere5 cluster in my test environment just for
testing, and playing around, with properly configured HA, and also DRS. I’ve created
various DRS policies, and tested a lot the cluster features throug a lot of scenario.
After that I started playing with VMware Update Manager. After configuration I ran into a
problem at the very beginning of the process when the Update Manager tried to place the
first ESX host into maintanance mode. The process were in stuck, and no error message at
After a while (I am usually patient when trying something new 🙂 ) I started
investigating, what the problem could be. I found quiet quickly that I hadn’t turned off
all the DRS policies, and one was active which forced 2 of my VMs running on different
hosts. This caused Update Manager not to be able to take the host into maintanace mode.
Turning off the DRS policy solved my problem, and Update Manager did the update