Blinded by the Virtualization Hype

In the virtualization race, organizations may be compromising their rollout gains by overlooking

InfoManagement Direct, November 5, 2009

Ed Hallock

The hype has been huge. The benefits, unbelievably good. But as loudly as we might sing its praises, it’s time for us to stop for a minute and admit something about virtualization: it’s harder to manage than we initially thought. Okay, it’s much harder.

If you’ve gone virtual (and most of us have — at least partially), you’ve probably already received a morning-after reality check: the difficulties of tracking roving virtual machines (VMs), tracking trends in VM usage levels and containing virtual sprawl. Through new technology and best practices, we’ve made some respectable progress in these areas. But an equally steep challenge lies ahead on the virtualization horizon: maintaining application performance.

For many virtualization adopters, applications have been an afterthought. Most IT teams have rushed to virtualize servers without considering the long-term impact of their actions. Few have paused to think about how the applications running on their VMs are actually performing from an end-user perspective. Yet, this is something we can’t ignore. Consider how much revenue is at risk when Web-based applications crash. For one of the world’s largest e-commerce businesses, going dark for just one minute can amount to tens of thousands of dollars in missed purchases. If the outage lasts one hour, revenue losses for the company could be millions of dollars.

We don’t have a lot of time to figure out how to manage the applications in VMs. Server virtualization is advancing at a breakneck pace, with no slowdown in sight. According to Forrester Research, virtual servers are expected to represent close to one-third of application deployments by 2011. According to IT Process Institute, 64 percent of organizations already aggressively pursuing virtualization initiatives are comfortable virtualizing business-critical systems. Before long, virtualization will touch every part of your organization, including the applications that are directly responsible for your business’s revenue stream. We simply cannot afford to get so enamored with the technology of virtualization that we ignore end users. At the end of the day, we need to be able to answer questions like, “What is happening now that prevents my customers from placing orders?” or, better yet, “What is going to happen next?”

Born to Run

IT’s fast-track attitude toward server virtualization reminds me of the lyrics to the Bruce Springsteen song “Blinded By the Light.”*

Yeah he was blinded by the light

Cut loose like a deuce another runner in the night…

To some extent, most of us have been blinded by the hype. Part of our surging excitement can be attributed to the way it has been (re)packaged — as a shiny, new “disruptive” technology. And then there are the benefits, which seem too good to pass up. After all, who would say no to consolidating 15 underused servers into one? And what about how quickly they can be deployed? Or the fact that virtualized servers can be moved to accommodate shifting workloads?

Virtualization has given many organizations more bang for their server bucks. Forrester Research reports that server consolidation via virtualization can save up to 50 percent in hardware costs – and even more, if you factor in lower energy consumption and improved disaster recovery.

This is all well and good, but if the applications running on these VMs aren’t performing, the cost-saving advantages of virtualization really don’t matter.

Worlds Apart

How well applications run in a virtual environment depends, in part, on virtual infrastructure performance. But to manage this effectively, organizations need different capabilities than were necessary in a physical environment.

I might think I know how to manage the performance of a virtual server, but once I deploy several, I will discover something very important: a virtual server is not just another server. I can’t run any application I want on it for one simple reason: it’s not a dedicated resource. Virtual servers share physical host machines with other guests, so the one-to-one ratio of a physical environment no longer holds. While the host may have abundant resources to support a VM, there’s no guarantee that the workload running in the VM will perform as well as it would in a purely physical environment (where it would be running on its own dedicated physical server). For example, I can decide to place two guests with an average use of 50 percent on the same host, but when their usage levels simultaneously peak at 75 percent, one of the VMs will have to wait while the other’s workload finishes—or possibly both will suffer performance degradation, impacting the applications running within the VMs.

Thanks to hypervisors, we have less guesswork in this area than we had five years ago. Not only do these tools track how much physical/hardware resources are being used by each VM, but they are also able to pool resources and allocate a pro rata share of physical host’s resources among multiple guest machines.

This sounds good, at least until we run into the all-too-common scenario of having to manage virtualization tools from multiple vendors.

Different people from different departments with different perspectives and different responsibilities use different virtualization tools. (Case in point: one department may concentrate on performance and availability, another may manage assets and a third may focus on capacity.) According to research from enterprise management associates (EMA), 98 percent of enterprises are using multiple virtualization platforms, technologies and vendors — on average three to four of each, and as many as 20 in total. A single organization can have hypervisors from VMware, Microsoft, Citrix and other vendors, scattered throughout its virtual environment. Inevitably, these diverse platforms will intermingle in the pursuit of specific initiatives.

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