The 411 on Virtualization

Updated: August 20, 2012

You've been living under a rock if you haven't heard the phrase "virtualization " in recent months. Research firm Gartner Inc . predicted that virtualization will be the highest-impact trend changing infrastructure and operations through 2012, and will transform how IT is managed, what is bought, how it is deployed, how companies plan and how they are charged.

Essentially, virtualization allows one computer to do the job of multiple machines by scattering the resources of a single computer across several environments. By running multiple operating systems and applications on the same computer simultaneously, virtualization increases the utilization and flexibility of hardware without any interference.

How Virtualization Works

There are typically two approaches to virtualization. Vendors such as VMware Inc . require users to install a software layer that lets multiple servers operate on a single piece of hardware. This layer, called a hypervisor, sits between the hardware and the operating system and presents an interface that looks like hardware to the guest operating system.

The second approach taken by vendors such as Sun Microsystems Inc . involves installing an operating system directly on the hardware. Various applications run in isolated areas called containers but they all share the same operating-system instance. Shares of the physical server's resources are then divvied up among the containers on a case-by-case basis.

Types of Virtualization

While virtualization comes in many different shapes and sizes, there are a few primary categories. These include:

Storage Virtualization: With storage virtualization , physical storage spaces from multiple network-storage devices are pooled together into what is viewed as a single logical unit that can be managed from a central console. The result is a one-stop shop for storage administrators to perform time-consuming tasks such as backup, archiving and recovery.

Server Virtualization: According to Gartner, server virtualization promises to unlock much of the underutilized capacity of existing server architectures by letting companies host multiple operating systems locally and in remote locations. In fact, as hypervisor prices drop, Gartner estimated that more than 4 million virtual machines will be installed on x86 servers by 2009. What's more, industry analysts reported that between 60 percent and 80 percent of IT departments are pursuing server-consolidation projects in pursuit of increased cost savings.

PC Virtualization: Forrester Research reported that about 18 percent of companies have implemented PC virtualization software, and another 8 percent plan to do so in the next year. What's more, the number of virtualized PCs is expected to grow from less than 5 million in 2007 to 660 million by 2011. By creating virtual machines, PC virtualization provides a secure environment of corporate-sanctioned programs for IT managers while giving employees the opportunity to access and configure personal applications and settings.

The Benefits of Virtualization

Virtualization technology offers a number of benefits, a handful of which are:

• The ability to host multiple operating systems and applications locally and in remote locations, thereby freeing companies from any physical limitations.
• More efficient use of hardware resources, which can lower capital expenses.
• Easier and faster desktop management for IT administrators.
• Improved disaster-recovery processes with a virtual infrastructure.
• Less power consumption from both the servers and facilities' cooling systems.
• The opportunity to write and test code in virtual, non-critical environments. Similarly, virtual machines can be used to provide secure, isolated sandboxes for running untrusted applications.
• Consolidating underutilized x86 servers in the datacenter can yield both immediate and ongoing savings.
• Making tasks such as system migration, backup and recovery more manageable.

The Players and Their Offerings

VMware: VMware Infrastructure 3 virtualizes servers, storage and networks to transform IT infrastructure into an automated, always-on system. Through VMware's products and services, companies can increase hardware utilization, lower power consumption and reduce capital and operating costs. In addition, users can run multiple unmodified operating systems on a single server by partitioning that server into multiple virtual machines, each with its own virtual processors, memory, networking and storage.

IBM Corp.: IBM's TS7700 Virtualization Engine is a mainframe virtual-tape solution designed to optimize tape processing. Through the implementation of a fully integrated tiered storage hierarchy of disk and tape, this engine can help accelerate backups and recalls; automate and simplify IT operations using advanced policy management; and reduce costs such as power, maintenance, operations and support staff.

Citrix Systems Inc.: Citrix XenServer is a native 64 bit virtualization platform with the scalability required by business-critical applications. The foundation of Citrix XenServer is the open source Xen hypervisor, a proven and fully supported engine for server virtualization. This software is easily installed with a CD or network-based installation.

What to Consider

Virtualization may promise cost savings, administrative ease and improved disaster-recovery processes but it has drawbacks as well. Here's what you should bear in mind when making a purchasing decision:

• With virtualization, virtual servers often require their own operating system, which can add to licensing costs and system overhead.
• By uniting disparate systems and/or applications, virtualization can make it difficult for IT managers to get to the bottom of a performance issue.
• Not all security systems support virtualization although steps are being taken by big-name vendors to boost compatibility.
• Performance conflicts can arise among some applications so IT administrators need to familiarize themselves with a virtualized datacenter's inner-workings and problem areas.