It has been a good couple of years for open source virtualisation product KVM. Available as part of Red Hat Enterprise Linux, SUSE Linux Enterprise and Canonical Ubuntu, KVM is now a serious competitor to established products such as VMware's vSphere, Microsoft's Hyper-V and Citrix's Xen.
In 2011, the Open Virtualization Alliance was formed by IBM, HP, Red Hat, BMC Software, Eucalyptus Systems, SUSE and Intel. Since then, it has gathered over 250 members many of whom are delivering solutions, such as management software, to make KVM a viable enterprise solution.
In terms of performance, KVM is no slouch. At the end of January 2013, it held the top 7 SPECVirt benchmarks. SPEC industry standard benchmarks are used by vendors to highlight the capabilities of their solutions and it is rare that an open source solution holds so many. Of more interest is that when put head to head with VMware, KVM outperforms it across 2,4 and 8 socket servers.
All of this sounds good and the list of end-users, especially large enterprise customers, is growing. Ask around at shows, however, and KVM is unlikely to be the first virtualisation product that many people mention. Talk to the very large cloud vendors and it is a different proposition. There are an increasing number of very large cloud providers who now offer KVM as an alternative to VMware and Microsoft. The interest is even higher when you look at the smaller cloud providers who have moved from being hosting companies to cloud providers.
The reason for this interest in KVM is twofold. The first is that a lot of these suppliers have an established history of delivering Linux. The second is cost because it is cheaper to deploy KVM than other virtualisation products. This wasn't always the case. Both Microsoft and VMware have increased the cost per virtual machine in recent years. KVM, as a newcomer, is therefore much cheaper.
If could be argued that this is never going to be a fair comparison because there are management suites and other products from the key virtualisation vendors that are tightly bound to their hypervisors. KVM, on the other hand, relies on a third party industry, OVA, to provide all of this and those products have to be licensed separately. However, if you just look at the cost per VM, there is a significant difference.
Take the case of international auction house Bonhams. They recently moved from VMware to Red Hat Enterprise Virtualisation (RHEV) and KVM due to cost, performance and capability. The cost savings alone, paid for the project work to do the migration. With VMware, 50 percent of their infrastructure cost was licences compared to 16 percent with RHEV. The resource friendliness of KVM also lead to a reduction in the hardware required to support the solution. More importantly, they were also able to put in a DR solution to support all of their offices, something that they found hard through the VMware offerings.
Cost savings alone, while attractive to many CIOs, does not make KVM a suitable enterprise cloud solution. What is needed is proof that it has the relevant cloud stack to make it easily deployable, is reliable and can support the solutions that the enterprise wants to move to the cloud.
At present, vendors such as IBM through its SmartCloud Enterprise solution, DutchCloud and SLTN in the Netherlands, Webb in Brazil, Rackspace and others, are deploying KVM to their customers. An increasing number of those, as in IBMs case, are enterprise customers.
The primary use of KVM in cloud seems to be as part of Infrastructure as a Service (IaaS) solutions. To help cloud providers get KVM into their environments, OpenStack, an open source project promoted by Rackspace and NASA since 2010, is using KVM as its core hypervisor. This is important for KVM. Without a cloud stack where KVM is a core component, it would have to be worked in to other stacks from cloud providers. This would take a serious amount of work, not least in the management tooling, and slow down KVM adoption.
Support from OpenStack is not enough, however, to make this enterprise ready. Few corporates are going to use OpenStack as part of their private cloud work. This is where the key OVA players come in. IBM and HP, in particular, now support KVM with their management solutions. As a result, enterprise customers do not need to change key parts of their own software stack in order to adopt KVM.
To make KVM a ready alternative for customers, cloud providers are already listing it as part of their self-service portals. This means that customers can deploy it just as quickly as other hypervisors and, more importantly, can see the cost, both monetary and in terms of compute resources, of using KVM versus vSphere, Hyper-V or any other hypervisor.
Another part of the maturity of KVM is the increase in the number of virtual appliances that are beginning to appear. This is still some way short of what is available on other hypervisors but is growing daily. IBM is already working on porting all of its virtual appliance to KVM and making it a first class platform alongside VMware and Hyper-V.
At the same time, there is a lot of work inside OVA and from smaller vendors to show how to port virtual machines from other vendors onto KVM. This latter step is particularly important as enterprise customers do not want to be supporting multiple hypervisor management systems. What is needed, therefore, is not just the ability to port other virtual machines to KVM but to manage KVM from other hypervisor management suites. There is still a lot of work to be done here.
The next step for KVM will be as part of a Platform as a Service (PaaS) offering. This is something that will take some time. When asked, IBM readily admitted that this is something that is unlikely to happen in the next 12 months. This is disappointing, especially as IBM has been promoting KVM on its PureSystems platform and at an analyst event in Madrid last December, spent a lot of time talking up its plans for PaaS on PureSystems.
There are a number of things that still need doing to make KVM as attractive an option to enterprise customers as vSpher, Hyper-V and some of the smaller hypervisors. However, KVM is already attracting enterprise attention and is cloud ready. In a world where the explosion in virtualisation is finally being felt in an explosion of license costs, KVM deserves serious consideration when planning IaaS deployments.
