Red Hat Summit: RHEL 5.4 released
Two months after the release of the beta version, Red Hat has released the fourth major update to its Enterprise Linux. Red Hat Enterprise Linux (RHEL) 5.4 is, for the first time, built around KVM which uses Intel VT-d virtualisation capabilities. This will provide the foundation for the, currently in beta, Red Hat Enterprise Virtualisation (RHEV) platform. Thanks to RHEL 5.4's built in support for the PCI-SIG standardised SR-IOV (Single Root I/O Virtualisation), PCI resources can be allocated to individual virtual instances when using a Intel Xeon 5500 based platform.
On the technical side, not much has changed since the beta version; the developers have mainly improved I/O throughput. RHEL 5.4 features an enhanced SystemTap, XFS file system, FUSE and numerous driver updates. The operating system has also had optimisations added for the Xeon 550 and for AMD's Istanbul platform. Full details of the changes are available in the release notes. Red Hat assures users of Xen, its previous virtualisation solution, that the technology will continue to be supported for the full life cycle of RHEL 5.
The developers of CentOS, which is based on the releases of Red Hat Enterprise Linux, say that CentOS 5.4 should be "released in 2-4 weeks or so, when it's ready".