When trying to enter a Host into maintenance mode one or more VMs may be stuck in this case we can try and manually vmotion the Stuck VM which may produce the following error.
Currently connected device 'CD/DVD Drive 1' uses backing '
packages/4.1.0/vmtools/windows.iso', which is not accessible.
The virtual machine is installing VMware Tools and connot initiate a migration operation
Error on PRDSQLRS01:The operation is not allowed in the current state.
Call "VirtualMachine.UnmountToolsInstaller" for object "PRDSQLRS01" on vCenter Server "DALVCS01.NDPA.int" failed.
To get around this without rebooting the Guest VM causing the issue we need to do the following.
1. Disconnect and remove the Host from the Virtual Center (dont worry the VM stays up)
2. Go into tech support console on the host and restart the management agents.
3. Add the Host back into the virtual center
2. Restart the management agents again.
4. Right click on the VM and go to Guest --> End VMWare tools install. wait 30 seconds and try and vmotion it again.