Avoid Virtualization Pitfalls
Five best practices for getting started with virtualization
reprinted with permission from HP
May 2010 NMGI Technology News
 

To save money on equipment and time on system maintenance, more and more businesses are deploying virtual servers. Reduced overhead and simplified management can free up resources that can be applied toward innovation and other valuable projects that sharpen the business' competitive edge.

But virtualization does have its pitfalls. Creating new virtual servers haphazardly can easily lead to out-of-control server sprawl. Stacking too many applications on one host can leave them competing for resources. And managing your virtual resources among your physical machines can get complicated, especially for IT staff accustomed to managing only one application per physical server.

Realizing the benefits of virtualization hinges on good planning, properly balancing your resources and employing the right skills and experience. Here are a few tips to help you avoid some of the more common challenges of virtualization.

Set expectations
In a traditional server environment, business units can come to expect full use of an entire server box, which usually provides more than enough capacity, making it seem like a bottomless resource. But the dynamic nature of virtualization means that resources are shared, as well as the cost of managing or acquiring them. Without clear guidelines and support from the rest of the organization, you may get conflicting requests or even refusals to virtualize certain assets.

Get business stakeholder participation and buy-in early to help you manage the transition to virtualization and ensure that it aligns with overall business goals. Be proactive about educating all affected stakeholders and users about how resources will be allocated and shared. Also explain the business benefits of moving to virtualization.

Balance resource needs
A major benefit of virtualization is increased resource utilization. But too many applications vying for the same resources may leave those applications competing for inadequate RAM, processor capacity, disk I/O or network bandwidth.

Before moving anything to a virtual server, take stock of your applications and their computing requirements. In particular, identify those that experience heavy spikes in demand for specific resources. Some of these applications may be better suited for traditional servers. Group the rest of your applications that don't rely heavily on the same resources. As a best practice, distribute your applications strategically across your virtual servers so that each has what it needs to perform well.

Don't overload physical servers
Getting your virtual assets to run smoothly and play well together is one thing. But keep in mind that they still reside on a physical host server, which also requires periodical maintenance and upgrades. If you're running multiple physical hosts, be sure to distribute your mission critical applications strategically, so that taking a single host server down for maintenance doesn't disable multiple mission critical applications at once.

Also keep in mind that virtual servers, like physical servers have cyclical resource needs that can spike dramatically when business processes are most demanding, whether that be weekly or once a quarter. Make sure you plan for these spikes when allocating resources for your servers and applications.