Seven vendors recently 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.