Virtualization software is stealing some traditional job functions provided by a server operating system (OS), but the latter will remain relevant in data center environments as long as it evolves to meet customers' needs, according to an industry analyst.
Phillip Sargeant, research director at Gartner, said the role of OSes is "definitely changing" but the majority of virtualized data centers still have an OS of some sort within their architecture.
"I've yet to see many virtual machines that do not contain a Windows, Linux or Unix OS," Sargeant said in an e-mail interview. But, he noted that traditional server OSes have to evolve in tandem with hardware platforms and data center requirements to stay relevant.
The analyst explained that these OSes must "increasingly broaden their awareness of dynamic factors", both inside and outside the platform, to continue serving the needs of enterprise customers.
"For example, as the number of processors and number of cores within each processor increase, OSes must learn to tune the software load to run on the available resources," he said.
The importance of server OSes is reiterated by Andrew Dutton, senior vice president and general manager of VMware Asia-Pacific and Japan, who noted that these platforms will continue to remain useful as they are needed to run applications.
However, Dutton also pointed out that the main tasks of an OS are to serve the underlying hardware such as the I/O, memory and network, and to interface with applications or middleware layers. The former function, however, is increasingly being taken over by the hypervisor or virtualization layer, he said.
"As the hypervisor or virtual layer takes the place of the main interface to the underlying hardware, the focus will shift to virtual applications that are optimized to run on the hypervisor," he told ZDNet Asia in an e-mail.
He noted that these "thin or just enough OS" will be a key feature in cloud architectures as they are "lightweight, resilient" and work well in the datacenter environment.
Furthermore, users will no longer have to deal with the "complexity" of configuring and managing the OS. Instead, the hypervisor will be responsible for the provisioning of hardware resources, Dutton added.
These developments are why "heavy, cumbersome server OSes common today are becoming less important" as cloud computing and virtualization increasingly become the standard in an enterprise architecture, he said.
In a previous report, VMware President and CEO Paul Maritz said virtualization and open development frameworks were squeezing out the need for OSes in data centers.
A Computerworld article cited Maritz to say that while there are still OSes underlying virtualized infrastructures, their traditional roles are being usurped by "new elements that are transforming the IT world" which companies are "embracing".
Diminishing role in data centers
Microsoft, one of the key server OS vendors in the market, also recognizes the shift toward virtualization and its growing importance.
Deepak Setty, regional manager, Microsoft Asia-Pacific, pointed out that virtualization is the "birthright" of every server and users should be entitled to benefit from this technology.
He cited the recent announcement made by VMware to partner Novell to complement its existing virtualization software with server OS technology as example of the "growing demand" for options that incorporate both server OS and virtualization platforms.
To this end, Setty mentioned that virtualization is "at the heart" of Microsoft's Windows Server software and its strategy of outfitting customers with products that allow for "maximum interoperability" have resonated well with customers.
According to VMware's Dutton, traditional server OSes such as Windows Server will have to ultimately accept a diminished role in the datacenter environment.
"With the increase in adoption of virtual appliances, the traditional server OS will continue to be used in virtualized environments for the next three to five years, but their role will be less important as they are no longer a key consideration in the cloud IT architecture," he said.