With the pending release of VMware’s vSphere 5 hypervisor, come some licensing changes… yet again.

Back in 2009 with the release of vSphere 4, VMware added another tier to the licensing model.  Whereas Enterprise had been the top license level, VMware added another level, Enterprise Plus.

Enterprise Plus gave you additional functionality, such as allowing support for over 256GB RAM per host, up to 8 vCPU per virtual machine, support for physical CPUs over 6 cores (such as AMD’s 12 core model), as well as vDistributed switches and host profiles.

The release of vSphere 5 adds some more license restrictions including the concept of a vRAM restriction.

According to VMware, vRAM or virtual RAM is the total memory configured to a virtual machine.  If you are licensed using the Enterprise model, you are licensed for up to 32GB in RAM allocated to virtual machines, per socket.  These numbers can be aggregated across your servers.

Example:

If you have 4 hosts each with 2 sockets, and each host has 64GB RAM, you have a total of 8 socket licenses of vSphere Enterprise, and 256GB RAM.  256/8 = 32GB, or the licensing limit for Enterprise.

If you have Enterprise Plus, you would have the ability to license up to 48GB RAM per socket, and would be able to have 384GB RAM on those same 4 hosts.

Other editions of vSphere 5 (Essentials, Essentials Plus and Standard) have 24GB vRAM entitlements per socket.  VMware is eliminating the vSphere Advanced licensing level.

VMware does not apply a hard ceiling on RAM restrictions, but the server will warn you if you are out of compliance.

For some good news, VMware has upped the vCPU restriction on the Enterprise licensing level.  with vSphere 5, you will be able to run 8 vCPUs unlike in vSphere 4 where you were limited to 4 vCPUs.

View VMware’s vSphere 5 licensing and pricing guide at:  http://www.vmware.com/files/pdf/vsphere_pricing.pdf