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.