We have a few ESX hosts which run a number of Windows guest OS instances. Due to the restrictions of Windows Standard licensing, I know that we can only have a certain number of VM's running based upon the amount of licences we have.
If all of our ESX hosts (with one processor) have one licence, I believe this means we can run two VM's. If we have HA and DRS active, then VMware may power-up additional VM's on another host due to hardware failure / maintenance or move them around based upon resource demand. If that happens, additional VM's may end up running on another host, breaching the licensing agreement.
If you had three hosts, each running two VM's and you allowed for a single host failure, then you would need to purchase 2 x Windows Standard licenses for each host? This would then accommodate the failure as you would be licensed for an additional two - whether it's an additional two VM's running on one of the remaining hosts or one on each of the remaining.
The problem is, surely DRS can move any of the VM's to any of the hosts, i.e. if you have an application that consumes a lot of CPU and memory, it may end up on one server only (wasting a license) and all the other VM's end up on another host which then breaches the licensing agreement?
Is there any way you can control the amount of virtual machines that can run on a single host to make sure that you are compliant with licensing?
I realise that Datacenter licensing would be a better way to go as the VM sprawl increases, but we want to avoid it for now.