Microsoft's free and fully-featured challenger

Microsoft is late to the virtualisation game, and it is the underdog in a market that is heavily dominated by VMware.

For that reason, Microsoft has had to come up with compelling reasons to switch to Hyper-V Server 2012. The reason most cited is that the hypervisor component is free.

But perhaps a more important point is that Microsoft's Hyper-V is, unlike VMware's solution, not feature limited.

VMware vSphere ESXi 5.1's free version has a hard limit of 32GB of RAM installed in a server. Any more than that, and the free license key won’t be accepted.

There were no such limitations on the enterprise version of Hyper-V 2012. It has a maximum physical memory limit of four terabytes for the host, with 320 logical processors and 2,048 virtual ones.

ESXi 5.1 can also support 2,048 virtual processors per host, but maxes out at 160 logical processors per machine. In normal use, the RAM limit imposed on ESXi 5.1 is most likely to be of concern, along with the two terabyte maximum size of Virtual Machine Disk Format data storage for VMs.

Clustering for resiliency and high-availability is also possible with Hyper-V Server 2012, with a maximum of 64 nodes and 8,000 VMs; whereas vSphere ESXi does not offer these in the free edition.

Licensing complexity

Getting more features for free is great, but for those at enterprise scale that might run the up to 1,024 virtual machines Hyper-V Server 2012 supports, the license cost for VMware vSphere products might not be such a concern in the grand scheme of things.

Working out the cost of VMware licenses is another matter. The company sells through value-added distributors in Australia that add margins for the larger solutions they sell.

In the small to medium enterprise area, there are Essentials Kits that bundles together the vSphere hypervisor and vCentre Operations Manager Foundation tool. These start at $560 for the cheapest Essentials Kit which runs on a maximum of three servers with up to two processors each, and an 8-way vCPU entitlement.

Paying $5,349 buys the Essentials Plus Kit adds High Availability features, vMotion VM migration or cloning, Data Protection and vShield Endpoint, but with the same server hardware limits as the entry level offering.

Double that price to $11,743, and VMware's Standard Acceleration Kit offers a six-processor license that can be scaled upwards with more license purchases. This adds the vSphere replication, health monitoring, Storage vMotion and Fault Tolerance features among others.

VMware got a good kicking by customers for its vRAM entitlement “vTax” licensing change in 2011 and had to back down on it. Tody, the Essentials kits comes with an unlimited vRAM entitlement, although the fact that it’s still there makes you wonder if VMware is thinking about bringing it back.

Note that as of writing, VMware released the specs for vSphere ESXi 5.5, which bumps up many of the vital stats above, hauling in Microsoft’s advantage.

Read on for more on hypervisor management and performance, and what's coming up in the next releases...