Red Hat has just released the Red Hat Enterprise Linux 5.2 Beta on Tue, 11 Mar 2008.:



Red Hat is pleased to announce the availability of the *beta*
release of 5.2 (kernel-2.6.18-84.el5) for the Red Hat Enterprise
Linux 5 family of products including:

  - Red Hat Enterprise Linux 5 Advanced Platform for x86,
    AMD64/Intel(r) 64, Itanium Processor Family, S/390, System p
    and System z
  - Red Hat Enterprise Linux 5 Server for x86, AMD64/Intel(r) 64,
    Itanium Processor Family, S/390, System p and System z
  - Red Hat Enterprise Linux 5 Desktop for x86 and AMD64/Intel(r)




This beta has some improvements in Xen virtualization:




* Virtualization Enhancements
  + Large System Support
    - Hypercall interface for NUMA topology discovery
    - Optimized placement at guest start up
    - Support in libvirt
    - Physical CPU support increase to 64 CPU/system
    - Large Memory Support increased to 512 GB/system
    - Network interfaces in para-virtualized guests no longer
      limited to 3
  + Libvirt Enhancements
    - Remote management support
    - Manage virtual machines from single instance of virt-manager
    - Enhance virt-manager capabilities to more dynamic management
  + Additional Hardware Support
  + Xen hypervisor rebase to 3.1.2
  + CPU frequency scaling for Xen kernels for reduced power
    consumption (see the Release Notes for list of supported CPUs)




 + Performance and stability improvements




All details can be found at here.