Seven vendors this week launched the Open Virtualization Alliance, an organization aimed at promoting the Linux Kernel-based Virtual Machine (KVM) for enterprise applications. Initially formed by Red Hat and IBM, the Alliance also includes Intel, HP, BMC Software, Eucalyptus and SUSE Linux and is aiming to attract others involved with enterprise virtualization. The members clearly hope that KVM can provide an alternative to VMware, though they appear to have slightly different aims: the hardware vendors want to commoditize the hypervisor, the software vendors to leverage it as a way to sell service and support.
KVM is a virtualization technology built in to Linux that enables the kernel itself to act as a hypervisor, running Windows and Linux guests in much the same way as VMware or Microsoft's Hyper-V. The Alliance won't actually take over responsibility for KVM, as it's an integral part of the Linux kernel, but its members are already heavily involved in its development. "Right now, it's our largest technical investment," Daniel Fry, IBM's vice president of open systems and solutions development, said in an interview. "I have about 60 or so engineers working in or around KVM."
The Linux vendors clearly see KVM as an opportunity to take on VMware, with Red Hat taking the most aggressive approach." When one company dominates an industry, innovation suffers, and customers pay the price," Scott Crenshaw, Red Hat's vice president and general manager of cloud business, said in a statement. "The open source community is breaking the stranglehold of closed virtualization."
For the hardware vendors, KVM is a way to shift the focus from the hypervisor to other areas such as management or services. "IBM is agnostic; one size does not fit all," said Fry. He emphasized that IBM remains committed to VMware and Microsoft's Hyper-V, likening the company's support of multiple hypervisors to its support of multiple chips.
While it means more competition for VMware and Hyper-V, the increased emphasis on KVM could be a bigger blow for Xen, the open-source hypervisor championed by Citrix and Oracle. Most of the Alliance members had previously supported Xen, with IBM a particularly strong proponent and major contributor to its development. However, the company is now focused on KVM. "IBM was a Zen supporter and we have customers using it," said Fry. "Xen was a very good first take, but KVM is cleaner; it's technically more elegant, takes less maintenance. "
Whereas Xen was written from scratch to be a standalone hypervisor like VMware, KVM is built in to Linux so it can leverage existing Linux components such as its scheduler and memory management. "One of the big advantages is that you get to take advantage of the entire Linux ecosystem," said Fry, which makes it easier to add new features. KVM's downside is that it requires hardware virtualization support through Intel VT or AMD-V, but this is now built into almost all processors.
The Alliance's own FAQ admits that KVM "isn't considered an enterprise-grade solution," but claims that this perception is out-of-date, citing performance benchmarks that show it beating other virtualization systems.
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