Virtual I/O

What Does Virtual I/O Mean?

Virtual I/O (VIO) is a technique used in enterprise environments to lower costs, improve performance and make server management easy and simple. The virtual I/O methodology allows a single physical adapter card to be seen as multiple virtual network interface cards (NICs) and virtual host bus adapters (HBAs), which operate just like conventional NICs and HBAs.


Virtual I/O may be known as input/output (I/O) virtualization.

Techopedia Explains Virtual I/O

In virtualized environments, server I/O plays a major role in deploying the server effectively and successfully. Virtualized servers are capable of running multiple applications at a time, and there is a constant demand for more bandwidth and connections to multiple networks and storage devices. Virtual I/O methodology helps in removing performance bottlenecks by binding I/O to a single connection. This single virtual I/O connection usually has a bandwidth that exceeds the server’s I/O capacity. In virtualized servers running I/O-intensive applications, the virtual I/O technique can help increase virtual machine performance as well as the number of virtual machines per server.

Some of the important features of virtual I/O include:

  • Cost Savings: Virtual I/O helps to lower costs by allowing easy and simple server management. The use of fewer cards, cables and switch ports further helps in reducing costs.
  • Fewer Cables: Virtual I/O requires only a single cable to connect servers to both storage and the network. Multiple I/O cables are thus replaced with a single cable that facilitates shared transport for all network and storage devices.
  • Increased I/O Density: Virtual I/O technique increases the I/O density by enabling more connections.
  • Simplified Management: Virtual I/O enables greater use of virtual NICs and HBAs while providing greater flexibility.
  • Space Savings: Virtual I/O enables more I/O connections to exist within a small space by consolidating all storage and network connections to a single physical interconnect.

Related Terms

Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…