RHEL 6 beta drops Xen
Red Hat has released the first beta-test edition of Red Hat Enterprise Linux 6, with improvements to virtualisation, scalability and power efficiency, among other updates.
The operating system was made available for download on Wednesday. It is the first to drop the Xen hypervisor in favour of the Kernel-based Virtual Machine (KVM) developed by Qumranet, which was purchased by Red Hat in 2008.
Red Hat added the KVM hypervisor to Red Hat Enterprise Linux (RHEL) alongside Xen with version 5.4, which was introduced in September 2009. It has been testing virtualisation products based on KVM since June 2009.
The company has always made it clear that Xen will be phased out with RHEL 6, and it has promised to provide tools and services to help businesses migrate their Xen-based virtual machines to KVM.
Dropping Xen will free Red Hat from the substantial work involved in maintaining two hypervisor code bases, the company said. It added that the RHEL 5 line of products will be supported by the company and its partners until 2014.
The open-source Xen hypervisor, version 4.0 of which was released last week, forms the basis for virtualisation products from a number of vendors — notably Citrix, which acquired Xen commercial sponsor XenSource in 2007.
RHEL 6 builds on KVM with performance, scheduler and hardware-support improvements, Red Hat said.
"Red Hat Enterprise Linux 6 blurs the lines between virtual, physical and cloud computing to address shifts taking place in the modern IT environment. Featuring updated core technology from the kernel to the application infrastructure to the development toolchain, Red Hat Enterprise Linux 6 is designed to meet the needs of the coming generations of hardware and software technologies," the company said in a blog post.
New virtualisation features include Svirt, a security feature protecting the guest and host from unauthorised access, as well as SR-IOV and NPIV for improving the performance of access to physical devices and Libvirt for kernel resource management.
The software improves power management with a time-keeping system that puts unused processors into the idle state more frequently. RHEL 6 also includes monitoring tools such as Powertop and tuning tools such as Tuned, allowing the system to adjust power consumption based on patterns of service usage.
Performance improvements include modifications to the kernel, a rewrite of the process scheduler and improvements to multi-processor lock synchronisation, Red Hat said.
Networking changes include better IPv6 support and a new Mac 802.11 wireless stack. RHEL 6 also includes the Ext4 file system, with support for larger file sizes, and the XFS high-performance file system.
The operating system supports large numbers of CPUs and large memory configurations. It includes new security features including the System Security Services Daemon (SSSD) for central management of identities and a sandbox feature in SELinux for the execution of untrusted content.
On the desktop, RHEL 6 introduces the automatic detection of display types and support for multiple displays, as well as new drivers for supporting Nvidia hardware, as well as updates to the KDE and Gnome desktop environments.
The RHEL 6 beta is available on the i386, AMD64, Intel64, System z and IBM Power platforms via Red Hat's website.
The platform competes with the likes of Novell's Suse Enterprise Linux and Canonical's Ubuntu Linux, which was initially designed as an easy-to-use end-user distribution but has more recently moved into the enterprise market.