Red Hat has released a new major version of its flagship server platform, Red Hat Enterprise Linux (RHEL). The RHEL 6 update brings some noteworthy improvements in key areas like virtualization and scalability.

Red Hat's acquisition of virtualization company Qumranet in 2008 led to significant changes in the RHEL virtualization stack. Red Hat has transitioned its customers away from Xen in favor of KVM, a native hypervisor originally developed by Qumranet that is favored in the upstream Linux ecosystem. KVM became the standard virtualization solution in RHEL 5.4 and is now fully integrated in RHEL 6. Red Hat's considerable development investments in KVM have continued to advance RHEL's virtualization capabilities.

Those of you follow the latest Fedora releases have likely already seen many of the new virtualization features introduced in RHEL 6. For example, kernel same-page merging—which can reduce the memory footprint on systems that are running multiple similar guests—debuted in Fedora 12 last year. Single Root I/O Virtualization (SR-IOV), which allows multiple guests to share a hardware device without compromising performance, is another important addition that we saw first in Fedora.

Red Hat offers increasingly sophisticated virtualization management, provisioning, and deployment tools with advanced features like live migration. Much of the underlying work to deliver this functionality is being driven by the company's oVirt project.

Virtualization performance is reaching impressive levels. Red Hat says that a virtualized guest environment offers between 85 percent and 95 percent of the performance that you would get by running on native hardware for CPU-intensive operations. It shows that the overhead of virtualization is decreasing and doesn't come with a serious performance penalty. The company also says that its virtualization technology is getting better at handling I/O-heavy workloads too, such as guest environments that run database software.

Aside from virtualization, Red Hat also emphasized its commitment to scalability and energy efficiency. RHEL 6 will have no difficulty powering new servers with 64 processor cores and 2TB of memory, the company says. It can support a theoretical maximum of 16TB of physical memory, assuming that anybody wanted to build a RHEL server with such specifications. The operating system can automatically put unused cores into a low-power state until they are needed, thus conserving valuable energy and reducing power costs.

During the press briefing, several of Red Hat's partners discussed the technical advantages of RHEL and the reasons why they have adopted the platform. One prominent example is SaaS vendor Salesforce, says that it has boosted its scalability and reduced its costs by migrating from SPARC-powered Solaris boxes to commodity x86 hardware running RHEL. This echoed one of the major themes of Red Hat's press briefing, which is that traditional heavy-metal UNIX has been relegated to a small market niche while Linux and Windows increasingly dominate the enterprise server space. On several occasions during the press briefing, Red Hat identified Microsoft as its primary competitor in the server industry.

RHEL 6 continues Red Hat's tradition of delivering a competitive server product for enterprise Linux shops. The company says that its platform is ready to deploy and will work consistently regardless of whether your target environment is a hypervisor, bare metal, or the cloud.