Quoting from InternetNews:
RHEL 4.5 is the first update for RHEL 4 to include Xen paravitualized kernels. Xen is the open source virtualization effort that Red Hat has already included in its Fedora community Linux releases and is part of Novell’s SUSE Linux Enterprise 10 release as well.
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“The virtualization in 4.5 is to let it be a paravirtualized guest on RHEL 5,” Joel Berman, product management director for RHEL explained to internetnews.com. “That means that RHEL 4.5 will allow any RHEL 4 customers to quickly run on RHEL 5.0 with the high performance that comes from paravirtualization and without requiring any special hardware.”
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The final release of update 4.5 is expected sometime after March 21, 2007…
Read the whole article at source.