I am looking at our vm infrastructure and there are alot of ! Out-Of-Date signs on my virtual machines for VMTools, I am considering doing a mass upgrade using the advanced command /S /v"/qn REBOOT=R" to avoid reboots.
Can anyone advise me if this would cause any further issues doing this inside of office hours?
If you're suppressing reboots then there shouldn't be major outages. What can happen though is that the network connection will be unavailable for 1 or 2 seconds while the vNIC driver is updated. In most cases this also means that the Guest OS re-initializes the NIC device, causing currently established TCP connections to be reset.