Virtualization is the theme of the LinuxWorld 2007 Conference & Expo this year, and that’s as it should be, according to industry veterans I’ve interviewed recently. Virtualization a big boon for Linux adoption and a way to steal some of Microsoft Windows’ thunder, they say. Overall, they agreed that succeeding in that space is a make-or-break proposition for Linux.
“It’s appropriate that LinuxWorld focuses on virtualization this year, because virtualization is a must-have for Linux,” said Jim Klein, Information Services and Technology Director for Saugus Union School District in Santa Clarita, Calif. “Without virtualization, Linux will fade away in the data center.”
Klein doesn’t think doomsday scenario is going to happen, however.
“From my experience, Linux and open source virtualization technologies are top-notch, certainly superior to Microsoft’s and reaching parity with VMware’s. The openness of Linux virtualization technologies make it easier to run multiple operating systems in one box.”
On the other hand, some industry vets think that Linux and Xen in its various forms have a lot of catching up to do, and they hope to see some significant announcements at LinuxWorld. Summing up this side of the equation, Alex Fletcher, principal analyst for Entiva Group Inc., said:
“Xen is definitely mature enough to warrant consideration by corporate accounts. Recent moves, such as Red Hat Enterprise Linux (RHEL)5.0 adding Xen as its fully-integrated server virtualization functionality are intended to spur corporate adoption of Xen, but will need time to play out. Granted, RHEL is a fully-robust operating system, but this is the first release that’s included Xen, giving risk-adverse decision makers reason to hesitate. Efforts like libvirt, an attempt to serve as a stable C API virtualization mechanisms, have potential but need to mature.”
Then again, others said, many factors weigh in Linux’s favor in the virtualization arena. For one thing, RHEL and SUSE are very robust enterprise-level operating systems. For another, Linux is not fully-dependent on Xen’s success, because VMware is optimized for Linux. The proven reliability of Linux in data center deployments is another plus. Indeed, consultant and author Bernard Golden believes that virtualization will pave the way for wider usage of Linux. Virtualization makes stability much more important, he said, because after virtualization more systems run on a single piece of hardware. In this situation, he thinks Linux is a better choice than Windows, as Linux has a better track record for both stability and uptime.
Virtualizing Windows-centric applications on top of Linux is a good path to follow, said Golden, author of the soon-to-be-released book, Virtualization for Dummies:
“For those companies that need to move aging Windows applications onto new hardware and want a more stable underlying OS, virtualizing Windows on top of Linux is a perfect solution. Also, Linux’s scalability marries well to two trends driving virtualization: the increasing power of hardware and Linux’s ability to scale across multi-processor machines.”
Microsoft-centric IT organizations probably won’t rush into virtualizing on Linux. In particular, said Golden, sticking with Windows could suit companies that are not ready to make a full commitment to building a virtualization-based infrastructure. He explained:
“The upcoming virtualization capability in Windows Server 2008 — and beyond, given that much of the previously-targeted functionality for Server 2008 has been dropped — will enable [those organizations] to extend the life of aging Windows-based apps. Of course, being able to extend the life of those apps will, to some extent, reduce pressure to migrate those apps to Linux or replace those apps with Linux-based apps.”
Such IT organizations usually move to virtualization using their existing hardware, rather than bringing in more modern, highly scalable hardware, said Golden. In these cases, there is less need to move to Linux. This strategy and the efficacy of using old hardware will be short-lived, in his opinion.
Microsoft-centric shops will also be encouraged to stay that way if Microsoft delivers the promised virtualization-friendly licensing terms for its upcoming Longhorn-plus-hypervisor release, said John Lair, business development manager for Prowess Consulting.
Linux may not gain even if Microsoft’s operating system and virtualization platform price tags are more than those of Linux and, say, Xen, according to Fletcher.
“There is a chance that the savings gained from consolidation will actually work to make Linux’s lower software acquisition costs less of a selling point,” Fletcher said. “Higher licensing costs for Windows aren’t as much an issue when fewer servers are running.”
Then again, Lair and others noted, virtualization will probably decrease the importance of operating system (OS) selection, shifting attention to application and virtualization platform choices. Kamini Rupani, product management director at Avocent, summed up this side of the equation, saying:
“Virtualization doesn’t help or hinder adoption of either Linux or Windows on the server side, because virtualization isn’t directly related to operating systems. Virtualization is about the hardware, about adding more virtual machines running on top of an existing hardware environment.”
In this point-counterpoint discussion, others said that Linux stands to gain even if virtualization devalues OS selection. These folks think that Linux will be the power, or platform, behind the scenes in virtualized enviroments.
“Linux is so easy to use and reliable that I think it will be used ubiquitously and not get much attention,” said Klein. “People won’t care that their VMs are running on Linux. Choosing Linux will stop being a big deal. Also, I believe that the majority of virtual appliances will be running on Linux, so that people will just drop them in without a thought about which operating system is inside.”
If this scenario plays out, Linux will return to its roots as a stealth OS. IT managers brought Linux into IT shops through the proverbial back door to use for applications that didn’t need top-level approvals. While it moved up to a more visible position in data centers, Linux also infiltrated cell phones and numerous other devices without fanfare. Today, Linux appears to be a front-runner as ISVs’ top OS choice for virtual appliances. Perhaps even Microsoft’s resistance is futile.