Hypervisors Compared: VMware Stands Alone
If you follow virtualization at all, you probably know who Chris Wolf is. Chris is a virtualization analyst for Burton Group, and for my money, the most knowledgeable analyst in the industry. That's why I wanted him as a columnist for Virtualization Review
magazine, and was delighted that we were able to snag him.
Earlier this week at VMworld Europe in Cannes, France, Chris gave a fascinating session on hypervisors. The basic idea was to compare hypervisor readiness for enterprise computing. A hypervisor had to have certain capabilities to be considered worthy in areas like high availability, networking, management and storage. He compared four hypervisors: VMware's ESX, Microsoft's Hyper-V, Citrix' XenServer 5, and Virtual Iron's Xen-based hypervisor.
Only one hypervisor met all of the criteria in the "Required" category of functionality: ESX. All the others came up short in one or more areas. Hyper-V, for example, was lacking in some high-availability areas like the ability to prioritize VM restarts in the event of an outage -- in other words, if the server goes down, which VMs get restarted first -- and a fault-tolerant management server. Chris did, however, point out some areas for improvement, like dynamic I/O buffering and virtual hard disk compatibility.
Some of XenServers shortcomings included the lack of 802.1Q VLAN trunking, and directory services integration for better security.
Virtual Iron's was the lowest-rated hypervisor of the four, lacking an enterprise support policy among other faults; it's worth noting, however, that Virtual Iron, by and large, prefers to stick to the small and medium-sized business shops, which have fewer needs.
There's a lot more to Chris' findings than that; he and several Burton Group colleagues spent three months doing comparison tests and going over every inch of these hypervisors; their results are quite thorough, objective and eye-opening. It's worth checking out as part of your virtualization decision-making process.
I will note, also, that we add some more perspective to these findings with our separate coverage of the raw performance of three of the four hypervisors Burton Group looked at (minus Virtual Iron), and come up with some pretty interesting numbers of our own.
Posted by Keith Ward on 02/27/2009 at 12:48 PM