How Red Hat and KVM Ease Virtualization Technology Transition - Post 2

Posted by Mark Teter, Chief Technology Officer
August 2, 2011

In our last blog post, we discussed how businesses everywhere are latching onto virtualization technology as a way to increase the utilization of their IT investments, reduce costs, and increase IT management efficiency. Yet despite these strategic benefits, the physical-to-virtual migration still concerns IT executives and CIO’s across three areas: security, performance and scalability.

Our last blog post covered the security concern. This blog post addresses the performance and scalability concerns with virtualization technology.


Another aspect of virtualization technology shrouded in misinformation is performance; converting your underutilized, over-built systems to virtual servers does not compromise their performance. In fact, performance on virtual servers can exceed those of physical servers though optimization. Plus, the overhead of virtualization technology is decreasing and Red Hat Enterprise Virtualization (RHEV) technology is getting better at handling I/O-intensive workloads, such as guest environments that run database and CPU-intensive applications.

KVM workloads take full advantage of virtualization-enhanced, multi-core CPU technology. Red Hat benchmarks have demonstrated that the highest computing workloads (SAP, Oracle, Exchange and Java) experience performance that is 90 percent, or greater, on KVM. Some workloads, Linux/Apache/MySQL/PHP (LAMP) workloads, for example, achieve up to 140 percent higher performance than physical machines. Tapping into virtualization technology's performance-enhancing wellspring could give your applications the boost they need.


KVM's multi-core technology exploitation also makes it far more scalable than adding more underutilized physical machines to your data center. Remember, scalability is less a question of how many systems you can spin up, than it is how well your systems perform under increased loads.

RHEL 6 virtual servers handle workloads quite well in stressed environments. For example, a 100 physical server application farm will scale significantly and perform admirably with fewer virtual systems. That’s because those servers can likely seek a smaller footprint once converted to a virtual server format. With the more efficient and hardware-optimized virtual infrastructure, you could probably even reduce the number of supported servers by 30-50 percent.

In terms of energy efficiency, RHEL 6 has no difficulty powering new servers with 64 processor cores and 2TB of memory. Actually, RHEV supports a theoretical maximum of 16TB of physical memory (assuming anyone wanted—and could afford—to build a RHEL server with such specifications). The operating system can automatically put unused cores into a low-power state until needed, thus conserving valuable energy and reducing power costs.

Moving Forward

Overall, Red Hat is still a little newer to the virtualization technology field than most of the other major vendors, which makes it one of the smaller players in the virtualization technology market. Considering its short history, it’s not surprising that many industry experts questioned Red Hat’s decision to switch its hypervisor from Xen to KVM just a couple of years ago. (Red Hat originally used the open source Xen hypervisor as its virtualization technology engine, until 2008 when it acquired Quamranet, creator of the KVM open source hypervisor.)

Though still a relatively new development, Red Hat’s decision to integrate KVM into RHEL was a strategic move—particularly when considering how KVM has improved some of the issues of P2V. Of course, most service providers continue to run Xen—which lends itself well to virtual private server deployments and has a longer track record in the market. However, KVM is a veritable virtualization technology. A growing number of companies believe it has matured enough that they feel comfortable deploying it in production. Although it’s unlikely to replace Xen altogether, KVM will provide an attractive alternative to Xen for many companies as it continues to develop.

About Mark Teter Before he retired from ASG in 2013, Mark Teter was Chief Technology Officer (CTO) and the author of 'Paradigm Shift: Seven Keys of Highly successful Linux and Open Source Adoptions.' As CTO, Mark regularly advised IT organizations, vendors, and government agencies, and he frequently conducted seminars and training programs.

Filed Under: Virtualization

0 Responses to 'How Red Hat and KVM Ease Virtualization Technology Transition - Post 2'

Leave a Comment

Please copy "b4x3YXBEaBo0StdhJCrmi9Cxr1tPZAat" into the field labeled "Uncaptcha"