In the roughly four years since a group of Cambridge University researchers delivered the paper “Xen and the Art of Virtualization” at the ACM Symposium on Operating Systems Principles, the Xen hypervisor virtualization project has become the poster child for the power of the open-source development model.
Backed by the efforts of some of ITs biggest players, Xen has quickly matured from a promising research project into a viable free software counterpoint to the proprietary VMware product line that has so far captured the lions share of the blossoming x86 server virtualization market.
eWEEK Labs has been tracking the progress of Xen since the project stepped onto the scene, and we can report that its time for enterprise architects to begin recategorizing Xen-based products out of their emerging-technologies buckets and into their evaluation queues.
Xen-based virtualization shakes out into two primary categories: There are operating systems that offer Xen virtualization as part of a broad portfolio for hosting applications and services, and there are products focused on packaging Xen as a slim layer of code that turns server hardware into virtualization appliances.
Version 3.5 of Virtual Iron Softwares Virtual Iron server virtualization product falls into the latter category.
Until about a year ago, Virtual Iron Software was focused on a different sort of virtualization—collapsing clusters of multiple machines into what appeared to be fewer computing pools. With the emergence of Xen, however, the company switched gears and inverted its approach, divvying up hardware resources into multiple virtual instances.
As we learned during our tests of Virtual Iron 3.5, the companys clustering background helped deliver a smooth server provisioning story, in which virtualized nodes depend on a central management server to come up fast and with relatively little preconfiguration.
Also treading the path of converting individual servers into virtualization appliances is XenSource, the company founded by key Xen project members to productize their work.
Since we last reviewed XenSources flagship product XenEnterprise in September 2006, the company has burnished the management tools it delivers and added support for unmodified guest operating systems such as Windows. XenSource also has been hard at work fleshing out partnerships with hardware-focused Xen stakeholders such as Advanced Micro Devices and Intel, as well as with operating system vendors including Red Hat, Novell and Microsoft.
Novell has been pushing Xen aggressively for some time now—first in its fast-moving OpenSUSE Linux distributions and, since last summer, in its production-focused SLES (SUSE Linux Enterprise Server).
While theres no question that Novells customers are interested in tapping virtualization for their infrastructures, its less clear whether companies will wish to host virtual instances atop a thick-platform solution such as SLES. XenSource and Virtual Iron argue that the thicker the virtualization platform, the more potential there is for trouble.
With its recently released Red Hat Enterprise Linux 5, Red Hat is working to demonstrate what a traditional operating system vendor can offer in terms of delivering a virtualization platform as part of an operating system product. RHEL 5s virtualization story builds on Red Hats clustering competencies, and were looking forward to putting the new operating system through its paces in our lab soon.
From our perspective, the most promising operating system-based platform for hosting Xen is the platform thats currently furthest away from shipping a stable Xen host environment—Suns Solaris.
Sun, which is on track to build Xen-hosting capabilities into a test version of its operating system this summer, has a head start on Linux-based rivals with its Containers virtualization functionality thats already built into Solaris 10 and its experience with machine virtualization on its SPARC platform.
Advanced Technologies Analyst Jason Brooks can be reached at firstname.lastname@example.org.