BOSTON — Kernel-based Virtual Machine, or KVM, is a growing Linux technology for virtualization. Speaking at LinuxCon this week, Red Hat Senior Engineer Chris Wright noted that the open source project is on track to meet some very lofty goals.
“We’re on track for total world domination,” Wright told the capacity crowd.
He might be joking, but KVM is certainly on a tear. The project has amassed a number of big-name contributors, like IBM, Novell and Intel. Red Hat itself jumped into KVM in earnest with its $107 million purchase of Qumranet in 2008, thereby setting the stage to distance itself from Xen, the rival open source technology it had previously used.
One reason that so many big players are investigating KVM: Wright explained that the technology is positioned to do well as enterprises migrate their workloads to the cloud. The suitability for KVM in the cloud is a message that Red Hat executives have been reiterating since 2009.
“KVM is just a kernel module that provides the ability to run virtual machines,” Wright said. “We’re riding on top of Linux and that’s one of the huge strengths of KVM.”
Wright said that KVM was originally very limited in the number of virtual CPUs that it could provide. He noted that new versions of KVM can now scale to 64 virtual CPUs.
In terms of I/O performance, Wright noted that developers have been working on improving threading and pooling to improve overall performance. And though scaling and performance will continue to be areas of focus for KVM developers, the project is already boasting impressive performance metrics.
According to Wright’s testing data, KVM can now achieve 85 percent of bare-metal performance for its virtual guest operating systems, while adding that high-performance I/O is not coming at the expense of additional CPU overhead.
“We want to be able to run lots of virtual machines fast,” Wright said. “So we’re increasing throughput put while improving CPU efficiency.”
For networking, KVM has some new features that will enable lower latency. Wright explained that with a technology called Vhost, networking is now more lightweight in terms of the resources it needs.
KVM is also benefitting from new ties to networking vendor Cisco as well, now supporting Cisco’s VN-Link technology, which makes networking infrastructure more virtual machine-aware.
Additionally, Wright explained that KVM is set to get support for what’s called “transparent huge pages,” enabling multi-megabyte memory pages that can be dynamically allocated from 4 kilobyte memory chunks. The addition, he said, will help improve the performance of virtual machines with memory-intensive workloads.