VMware makes a great virtualization bundle available for any size organization but it really hits the “sweet spot” for SMB’s. VMware vSphere Essentials is a license bundle that gives licensing for up to 3 physical servers, up to 6 CPU’s (think CPU sockets) and up to 192GB of RAM across those servers (32GB per CPU). You also get a vCenter license to manage the hosts and VM’s. We (itgroove) use this licensing quite often for our SMB customers because it gives the best bang for the buck and allows SMB’s to access the broader feature set of licensed vSphere as opposed to just the basic hypervisor features you get with the “free” version of vSphere.
The following gives the licensing highlights as pertains to RAM which is the big change with vSphere 5 (from our internal blog at itgroove):
vSPhere 5 now imposes vRAM limits on a per physical processor basis. What this means is the amount of RAM that can be accessed/addressed by a single CPU (think processor socket) is limited by the license applied.
In practical terms this means that in an Essentials install (the three physical server bundled deal) the max RAM that can be accessed by a single physical CPU is 32GB. Therefore, as Essentials allows for up to 6 sockets, the total amount of RAM that can be addressed across ALL CPU’s is 192GB. So, a dual-socket machine can have a maximum of 64GB installed. vRAM limits also apply to VM’s and the max RAM a VM can have is 32GB.
The limits go up as you go up the vSphere licensing ladder but most of our customers fit into the above model. Also note that there are no real limits based on CPU cores; a single CPU socket can have a CPU of 1, 2, 4 or even 6 cores As an example, our Dell R510 has dual qaud-core CPU’s and our Dell R515 has dual 6-core CPU’s and both machines use the exact same vSphere licensing and both machines could have up to 64GB of RAM and still be within license limits.