I have read documents and found links that describe the new license model but I still can't get my head around it. Maybe asking specific questions will help.
Lets say I have 1 ESXi server with 2 physical CPU's with 48GB of RAM. How many licenses do I need?
What if I have the same ESXi machine with 1 CPU and 48GB?
What if I have 2 servers in HA and both have 2 physical CPUs and both have 48GB RAM?
I know that the licensing is based on the total amount of vRAM assigned to running VM's but how does another CPU affect the situation?
I have 1 ESXi machine with two CPU's and 48GB RAM on v4 essentials plus license currently. In v5 the Essentials Plus is a 24GB vRAM entitlemant. What the heck does that mean?
What happens when I add a vCenter server and another ESXi for HA?
Let me try to explain this.
First of all, each physical socket (CPU) needs to be licensed, regardless of the vRAM usage.
The vRAM entitlement covers the sum of memory assigned to all powered on VMs. In a clustered environment, the vCenter Server pools the vRAM entitlement.
With vSphere Essentials (Plus) you have an vRAM entitlement of 192GB (6 CPU licenses with 32GB vRAM entitlement each). The VM's may be powered on on one host with a single CPU or on all 3 hosts with 2 CPUs as long as you don't reach the vRAM entitlement.
Similarly to what AP said, think of it as a 'pooled' environment. With Essentials Plus, you're entire 'pool' of ESXi servers can use up to 6 physical CPUs and 192GB of RAM. It doesn't matter is 1, 2, or 3 servers are utilizing those resources (although Essentials Plus does limit you to a max of 2 processors per host).
vRAM is simply how much RAM your powered on VMs are using. If you have 5 VMs, each with 8GB of RAM, they would be using 40GB of vRAM (assuming they're all powered on). If only 1 VM is powered on, it is only consuming 8GB of vRAM.
vRAM is really no different than licensing processors, except in vSphere 5, you have to license both vRAM and sockets. This change was obiviously met with a fair amount of criticism... Just see some of the licensing threads with thousands of messages...
I have attached the VMware vSphere 5 Licensing PDF along with this post. Which will help you out to get clear idea about V5 licensing.
Also for example If your host has dual processor & if you have vShpere 5 enterprise plus for 1 processor (with 96GB vRam entitlement per processor) 8 CPU(s) then you can use this license for 4 dual processor host and if you have single processor Host then you can run 12 host on that license.
Enterprise and Enterprise plus support HA, DRS ferature.
... if you have vShpere 5 enterprise plus for 1 processor (with 96GB vRam entitlement per processor) 8 CPU(s) then you can use this license for 4 dual processor host and if you have single processor Host then you can run 12 host on that license.
Are you sure!?
I suggest you re-read that licensing document.
A license for a single processor, can only be used on a single host, regardless of how many cores the processor has.
A dual processor host will require 2 licenses.
To properly license 2 hosts, each containing 2 processors, requires a total of 4 licenses.
A single processor license can not be allocated accross multiple hosts under any circumstances, regardless whether it is a Standard Edition, or Enterprise Edition license..