Red Hat on Wednesday launched the fifth update to Red Hat Enterprise Linux (RHEL) version 5, RHEL 5.5, adding virtualisation improvements, tweaks to Windows 7 interoperability and support for new hardware platforms, according to the company.
The update is the first since RHEL 5.4 in September last year, which introduced the Kernel-based Virtual Machine (KVM) hypervisor alongside the Xen hypervisor.
Red Hat acquired KVM developer Qumranet in September 2008, and in June 2009 began beta-testing a new line of KVM-based virtualisation products called Red Hat Enterprise Virtualization (RHEV).
The latest release includes a number of new virtualisation features, including support for the large memory systems of new servers, which allows a larger number of virtual machine guests to be deployed per physical server.
RHEL 5.5 now automatically extends support for large virtual memory pages to virtual guests, improving the performance of memory-intensive applications, Red Hat said. It supports Single Root I/O Virtualisation (SR-IOV), improving the ability to share input-output (I/O) devices across virtual systems.
Another tweak makes it easier to reassign I/O devices, making it easier to migrate virtual guests across physical systems, Red Hat said.in a statement. "In combination, these enhancements aim to allow large-scale, I/O bound, enterprise applications to be readily virtualised."
Red Hat said it has also improved Windows 7 interoperability, extending Active Directory integration, improving user and group mapping and simplifying filesystem management across platforms. The software adds support for several new server hardware platforms, including Intel's Nehalem EX, AMD's Opteron 6000 Series and IBM's Power 7.
RHEL 5.5 maintains application compatibility and certification continuity with the RHEL 5 platform, meaning applications certified for previous RHEL 5 releases remain certified for the new edition. The software is available as of Wednesday via the Red Hat Network (RHN).
Microsoft and Red Hat said in October they had completed interoperability testing of their operating system and virtualisation products. The process included validation and support for RHEL running on Microsoft's Hyper-V hypervisor, as well as Windows Server running on RHEL using the KVM hypervisor.