Red Hat's just delivered the 5.2 version of its venerable Red Hat Enterprise Linux, right on the heels of the version 9 release of the equally-venerable Fedora.  I took some time out to talk with Daniel Riek, product manager for RHEL, about what was new. The best new stuff all involves the "V"-word: virtualization.

The first thing Daniel wanted to note is that 5.2 is a refresh, a minor release to enable new hardware -- but a lot of those "minor" changes make RHEL all the more appealing to those running data centers or performing server consolidation.  Many of the new goodies revolve around virtualization improvements, like support for larger systems (up to 64 logical CPUs) as well as NUMA and CPU frequency scaling controls.  This last item helps keep consolidation servers running that much cooler and save that much more power, something weighing heavily on everyone's mind these days.  (I should note that these things did exist before in the "bare metal" version of the product, just not in virtualization.)  And as per Red Hat's policies about code, these new features are developed as far upstream as possible.

Another key improvement to RHEL's virtualization comes in the form of the libvirt virtualization and management API.  This library's hypervisor-neutral, so it can integrate with a variety of management suites such as IBM/Tivoli's, which they're preparing compatibility with right now.  The timing's right for adding these features, especially since Microsoft is all the closer to rolling out Hyper-V as a solution of its own. 

In the same big-box / big-customer vein is a new set of high-availability clustering integration functions, like a new scripting language for controlling clusters.  Less obvious at first as a big-customer feature was their enforcement of the SHA-1 algorithm for passwords, but Daniel explained it this way: "I just got off the phone with a large customer on Wall Street" (no prizes for guessing!) "that was really pushing for this, because government regulations that they use as guidelines for security require you to move away from MD5."  I don't blame them.  They're also adding SHA-1 to RHEL 4.7 when that comes out, so people still cruising along on older installs of RHEL are not going to be left out in the cold.

What turned out to be most surprising for me was some of the new software for the desktop -- they've bitten the bullet and added the Firefox 3 release candidate to the out-of-the-box installation.  They feel it's polished enough at this point and close enough to a worthy release that they decided to include it.  "We did a lot of QA on that, and it was at least as good as what we had before," Daniel said.  My own (admittedly limited) experiences with the release candidate -- which I'll have something to say about tomorrow -- do bear that impression out.

The mix of virt features in RHEL is a strong hint that virtualization on enterprise-class Linux needs to work out of the box in both directions.  The distro has to work well with hypervisors or VM apps and be a good virtualization host as well; it translates out to that many more places that the distro can be dropped and will always land on its feet.