According to IDC's Worldwide Quarterly Server Virtualization Tracker, the overwhelming majority of IT shops using virtualization in a production environment are working with VMWare products. They may be running Windows in their enterprise, but those Windows environments are running on the VMware platform in many cases. Hyper-V, Microsoft's entry into the market, is gaining ground, but several factors may keep IT admins loyal to VMware. It has a bigger head start in this space, has a very stable product with a history of reliability, and has a loyal following (if attendance at VMWorld last week is any indication).
[ Read J. Peter Bruzzese's first installment in this two-part series: "The hypervisor wars rage on: A look at the new Hyper-V R2." | To learn more about vSphere 4.0, see InfoWorld's "The once and future virtualization king." ]
I had a chance to interview David Davis, one of the leading technical trainers for Train Signal and a vExpert, which is an award similar to the Microsoft MVP. The vExpert title is given to individuals who have significantly contributed to the community of VMware users and helped spread the word about virtualization over the past year.
So to start with, what exactly is vSphere?
VMware vSphere is a suite of products. The vSphere suite replaced the previous version of the suite called Virtual Infrastructure. vSphere is sold in various levels, depending on what features of the suite you want. All levels of vSphere include VMware ESX or ESXi (commercial, not free) and you must buy some version of vCenter. Examples of some of the features in the vSphere suites are VMHA, SVMotion, and the new Fault Tolerance (FT), which lets you run twin VMs in tandem across two hardware nodes, but with only one visible to the network so that if the primary goes offline, the backup VM takes over with no application outage.
What is the difference between vSphere and ESX?
vSphere is the suite of products, while ESX is the hypervisor that you load on each server that will participate in the vSphere virtual infrastructure. ESX commercial is available in "full/classic" and ESXi versions. It's important, however, that readers not confuse ESX with ESXi Free Edition -- these are very different. ESX is a part of vSphere enterprise virtualization suite, whereas ESXi Free Edition is for small businesses that want to get started in virtualization.