The CentOS community released its Red Hat Enterprise Linux (RHEL) 6.0 clone, promising continuous release updates to support RHEL 6.1 security features. In addition to supporting RHEL 6.0 improvements such as faster virtualization, and better scalability, power efficiency, and resource management, CentOS 6.0 is said to offer a completely rebuilt build system and library checks to confirm upstream binary compatibility.
CentOS 6.0, or “CentOS-6.0” as the community prefers it, is compatible with the Red Hat upstream release EL 6.0 and includes packages from all variants, says the community. As usual, this is an almost identical, 100 percent binary compatible clone of RHEL.
CentOS 5.6 shipped in April, about six months after RHEL 5.6 was announced and four months after the final was released, but CentOS 6.0 follows RHEL 6.0 by almost nine months. Obviously, the close release of the two updates — which also represent separate Red Hat product lines — slowed the community-based CentOS project, as did the major changes in RHEL 6.0 itself.
Making life for CentOS developers even more challenging, Red Hat announced RHEL 6.1 in May, and now offers general availability for the final version. Changes in RHEL 6.1, including touted virtualization performance optimizations, new hardware enablement, improved operational efficiency, and high availability improvements, will be available to CentOS 6.0 users via a Continuous Release repository. This will bring all 6.1 and post-6.1 security updates to all 6.0 users prior to a formal CentOS 6.1 release, says the community.
Despite being late, CentOS might find even more takers for its free version of the enterprise focused distribution than usual. With RHEL 6.0, Red Hat increased the starting cost of a supported edition of the product from $349 per year to $799 per year.
Virtualization, energy efficiency, and scalability enhancements
As Jason Brooks noted in his December review of RHEL 6.0, the release offers a strong foundation for hosting virtual workloads, complete with distinctive capabilities such as security features rooted in SE Linux. These enhancements, as well as improved cloud computing support and other improvements, appear to flow fully into CentOS 6.0.
The RHEL 6.0 release was primarily touted for virtualization performance improvements, with virtualized guests claimed to achieve 85 percent to 90 percent of native performance, thanks to a kernel-based virtual machine. Red Hat also worked on kernel improvements and power management to make RHEL 6.0 more power-efficient, with the release claimed to use 40 percent less electricity.
Other major changes target “future-proof” scalability. For example, RHEL 6.0 is claimed to support up to 16TB of memory and 4,096 CPUs, and can support a 100TB file system under a single OS, claimed Red Hat. Presumably similar benefits also await CentOS 6.0 users, even if the hardware systems have yet to arrive to test them out.
According to the CentOS community, CentOS 6.0 has been completely rebuilt using a newer build system, with library checks to confirm upstream binary compatibility. It is recommended that CentOS 5.x users completely reinstall the product rather than update it.