By Jason W. Eckert
Its no secret that virtualization is a hot technology today. Plenty of companies are implementing it, and VMWorld 2007 drew a crowd of over 10,000 people!
A few days ago I invited Scott Elliott, an expert on VMWare virtualization, to give a talk in my Network Security class about the benefits of virtualization.
Scott spent a good deal of time outlining how virtualization technology works, the benefits of using virtualization, as well as how virtualization impacted his IT infrastructure at Christie Digital (www.christiedigital.com).
In many network environments, servers are often used at 5-15% of their maximum load capacity. By using virtualization, a single “virtualized” server can be used to run several different operating systems at the same time, each with a different role (DNS, AD, SQL, Exchange, etc.). Virtualized servers typically run about 70-80% of their maximum load capacity, and hence make better use of the same hardware, save electricity and reduce costs.
In addition, each virtual operating system (i.e. Windows, Linux) that is run on a virtualized server is stored in a single file on the hard drive (called a virtualization file). To back up an entire operating system, you simply need to back up the virtualization file. Similarly, you can add additional virtual operating systems by copying virtualization files and customizing the settings afterwards. These result in safer data and less administration. It takes about 20 minutes to copy an existing virtual operating system compared to the 8 hours typically used to install an operating system on its own server hardware.
Another important benefit to virtualization is seen when implementing several virtualized servers that store their virtualization files on an external shared storage device such as an iSCSI or Fibrechannel Array. If a virtual server fails, its virtualization files can be immediately activated on one of the other virtualized servers such that these virtualized operating systems remain available. Similarly, if one particular virtual operating system needs more resources (i.e. SQL reports at month-end), then other virtual operating systems can easily be temporarily offloaded to other virtual servers. This allows the particular operating system more access to the virtual server hardware and far better performance as a result.
Perhaps the most important benefit to virtualization, however, lies in it lower costs. Instead of implementing 11 servers and operating systems, Scott chose a virtualized solution for the same price that could support 50 virtualized operating systems. Not only does this virtualized solution use less electricity, require less administration, and have more fault tolerance, it is also a fraction of the cost.
According to the IT research firm Gartner Inc., companies that do not use virtualization will likely spend 25% more for their computing infrastructure. If this is true, it may only be a matter of time before all organizations employ virtualization technologies.
For those of us who have yet to embrace virtualization, perhaps its time for us to add virtualization to our IT skill set.