Is it time to give KVM hypervisor a go?

An alternative approach to virtualisation

Binary over monitors abstract

Most organisations have coalesced around VMware's vSphere, Microsoft's Hyper-V and Xen as their choice of hypervisor – the platform that supports virtualisation of their IT resources - but there is an open source alternative in the form of KVM (Kernel-based Virtual Machine).

This hypervisor is fast gaining ground with backing from the likes of IBM, HP, Red Hat, BMC Software, Eucalyptus Systems, SUSE and Intel. They are educating users on best practice on deploying this type of hypervisor, largely to promote an open environment for competition against the likes of VMware and Microsoft.

So why should a small or midsized business look at this alternative?

The number of companies behind it can give it the edge over the VMware or Microsoft-backed solutions, as the broader ecosystem can prevent vendor lock-in and provide a more competitive market.

KVM has been promoted by the companies mentioned above as part of the Open Virtualization Alliance, which was formed in 2011 to promote it as a viable alternative to vSphere and Hyper-V, and to encourage companies to develop products such as management software to make it a viable proposition.

Cheaper infrastructure

For the IT manager running infrastructure in an SMB, KVM gets the most out of the hardware it is placed on, which means cheaper infrastructure costs. In the latest SPECVirt benchmarks (developed by the not-for-profit Standard Performance Evaluation Corporation), the technology more than holds its own against VMware's ESXi (which costs considerably more).

This is one of the key value propositions for KVM: it has the potential to reduce the overall cost of virtualisation. IBM did some calculations on the cost of running KVM against VMware and Microsoft, and for a 100% Linux workload scenario, VMware worked out 42% more than KVM over three years.

But many IT professionals know that cost alone does not make a virtualisation technology any good. With cloud becoming more prevalent, virtualisation has to work well within an organisation's cloud and be easily deployable within that organisation's infrastructure.

The one cloud technology that has taken KVM to its heart is OpenStack, the open source infrastructure-as-a-service (IaaS) . This platform has been backed by Rackspace and Nasa for the past three years and uses KVM as its core hypervisor. This means that KVM can now be part of an organisation's IaaS, and OpenStack has management software to deploy virtual machines running on KVM hypervisors.

It has to be said if KVM wasn't a core part of OpenStack, its adoption within the industry would have been much slower.

Admittedly, OpenStack is not going to provide the incentive for many IT managers to use KVM in virtualisation or on their own private cloud, but HP and IBM also support the hypervisor with management tools, enabling their customers to adopt KVM.

For those wanting to use open source virtualisation management tools to administer KVM hypervisors, oVirt is one such option and is backed by Red Hat. It is focused on KVM but as it is built on the libvirt (a virtualisation API within Linux), and can also manage Xen and VirtualBox hypervisors as well. This toolset forms the basis for Red Hat's Enterprise Virtualization product.

Cloud options

For IT managers willing to use public clouds, KVM is listed by quite a few cloud providers in their self-service portal, allowing for the fast deployment of virtual machines running atop the hypervisor. Notably, in these instances customers can compare the cost of KVM against Hyper-V and vSphere as well as their compute resources.

Another sign of maturity is the number of virtual appliances now available to run on KVM. It is nowhere near as big as for vSphere and Hyper-V, but moves by IBM to port all its virtual appliances to the technology is a indication of the intention of some players in the industry to make it a viable alternative to the market leaders.

Over the past few months, IBM has made a big push with KVM, opening up centres of excellence in Beijing and announcing another in New York devoted to stimulate the adoption of the hypervisor. It sees strategic advantages in KVM, believing its presence in the market can keep prices low and affect the way competitors do business, and that its direct access to low latency improvements to the Linux kernel makes it attractive in running high performance workloads.

IT managers can benefit from vendors that use KVM to bring simple, easy-to-use and affordable virtualisation to the mass market. It doesn't require licence fees for most of its functions and can enable access to enterprise software that's as easy as downloading the latest app.

Admittedly, KVM still needs more work to make it as attractive a proposition as vSphere and Hyper-V, but as licence fees for other hypervisors are now climbing, its appeal is likely to grow.