Virtualization technology has long found a home in Red Hat’s Fedora community Linux distribution. Ever since Fedora 4 emerged in 2005, virtualization technologies have continued to advance in the distro and that remains the case with the upcoming Fedora 13 release set for later this month.
Unlike Fedora’s early virtualization features, which all leveraged the Xen open source technology, more recent Fedora releases have relied on KVM. New KVM performance and scalability features for virtualization will debut in Fedora 13 that will help to push the envelope for large-scale virtualization deployments.
“If you look at Linux virtualization features, Fedora has always been the vanguard for virtualization,” Fedora Project Leader Paul Frields told InternetNews. “We were putting out KVM before anyone else and we were interested in KVM as it seemed like a much more upstream-friendly feature. Although Xen was definitely a virtualization focus for a few years, Xen had some drawbacks.”
Frields noted that from Fedora’s perspective, Xen had become a drain on resources for developers since it took a lot of work to get Xen to work together with the Linux kernel for a Fedora distribution release. He added that, in his view, the code base for Xen didn’t track exactly with the upstream Linux kernel and as a result, there was a mismatch.
“KVM changed all of that because of the fact that it is part of the upstream Linux kernel,” Frields said. “It has allowed us to focus our resources to devote more time in advancing the usability of virtualization.”
Among the new KVM features that will debut in Fedora 13 are KVM Stable PCI Addresses and Virt Shared Network Interface technologies. Having stable PCI addresses will enable virtual guests to retain PCI addresses’ space on a host machine. The shared network interface technology enables virtual machines to use the same physical network interface cards (NICs) as the underlying operating system.
Frields explained that those two new features will make it easier for administrators to automate their work.
“If you’re trying to automate the creation of machines and the way that they share particular bus connections on a host machine, you want to be able to definitely connect it to a particular bus,” Frields said. “When you can predict that, you can take advantage of a greater scale of automation.”
Another new virtualization feature debuting in Fedora 13 is the ^7Frields8^, which is about delivering improved performance. The ^9Frields10^ technology is intended to lower the CPU requirement for Advanced Programmable Interrupt Controller access, or APIC (define), which is used for program timers.
While Fedora is including the new advanced features for scaling virtualization, Frields doesn’t necessarily expect that Fedora will be the platform used for large-scale deployments.
“Fedora is a way for people to have a bit of a crystal ball where they can look into the future of Red Hat Enterprise Linux,” Frields said.
Red Hat recently released the first beta for Red Hat Enterprise Linux 6 (RHEL 6). As is the case in Fedora, RHEL 6 no longer includes Xen, but instead leverages KVM as the key virtualization technology for Linux. Features that first debuted in Fedora releases are now finding a home in RHEL 6.
“When people look at RHEL 6, they will be seeing the very recent past and present of Fedora,” Frields said. “The RHEL roadmap is always oriented towards long-term stability while Fedora will move on and forge new paths and will help define Red Hat Enterprise Linux 7 at some point in the future.”