It was all the buzz this past week: EMC VMware has changed its licensing with vSphere 5 from a model that is based on processor cores and physical memory to a model that charges based upon both a per-CPU-socket price (as it was before) and virtual memory (vRAM), which is the amount of RAM you might allocate to a system regardless of the physical memory within the machine. The vRAM is broken up into entitlements based upon the edition you purchase.
The way the new license structure works is that each license comes with an allocation of memory assigned to a number of pools and shared among the virtual infrastructure. With the following editions you get the vRAM amounts listed:
- Standard Edition: 24GB per CPU license
- Enterprise Edition: 32GB per CPU license
- Enterprise Plus Edition: 48GB per CPU license
[ InfoWorld's Savio Rodrigues says the new VMware licensing could drive IT to using more open source virtualization. | Ted Samson covers the vSphere 5 feature set in his column "VMware unleashes vSphere 5 and souped-up cloud suite." | Stay abreast of key Microsoft technologies in InfoWorld's Technology: Microsoft newsletter. ]
The vRAM from all the licenses you own is pooled or added up on the vCenter server. If you need more vRAM, you have to purchase additional CPU licenses for the edition you use. You cannot share excess vRAM allowance between editions, although you can share within pools on the same edition. And keep in mind that this is not referring to RAM that is actually being used but rather RAM that is simply allocated or configured. Many organizations overallocate RAM through an overcommit strategy; now they must reevaluate their virtualization structure.
Some people believe the entitled vRAM allocation is too low, but VMware says it calculated the allocation based upon the averages of its customers' deployments. The average VMware customers use a "5:1 consolidation ratio on their hosts (five virtual machines for every physical CPU socket), and on average, customers configure 3GB of memory per virtual machines," reports David Davis, a VMware vExpert.
Nobody is disagreeing that vSphere 5 is an impressive suite with powerful features that give VMware another leap ahead of rivals Citrix, Microsoft, and Red Hat. But this licensing punch in the gut has many administrators rethinking their need for the "best" virtualization solution and looking back to what Microsoft offers, which -- in my opinion -- is a very good, affordable, and ever-improving virtualization product that, when combined with System Center tools, is competitive with vCenter. Obviously until Microsoft releases Hyper-V Version 3, it will be difficult to say if VMware's current advantages remain unique.