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High Availability

Virtualization technologies are also playing a key role in Wachovia's second strategy, achieving high availability by default.

Hall says while Wachovia is adopting machine virtualization technologies like VMWare it also wanted to take a look at other ways virtualization could have an impact—from the number of drivers on a machine, to the number of cards, and the amount of change that was involved when adopting a new process or technology.

As a result, the bank began experimenting with building "processor arrays," essentially dense blade racks with no local storage and no directly connected input/output (I/O) devices (such as Ethernet or fibre channel cards, hard drives, etc.). To make this happen, Wachovia piloted virtual I/O technology.

One of the benefits of server virtualization is that several operating systems hosting applications can be moved onto a single machine, making better use of its capacity. However, one of the problems this creates is the applications end up sharing all of a machine's resources, including the connections to the network and storage. The typical solution is to add more I/O devices, such as Ethernet or fibre channel connections, a high-speed data transmission technology often used to connect services with clustered storage devices. The additional I/O devices provide more throughput and can be used to secure an application from being exposed to other networks.

Virtual I/O technology provides a means to consolidate all the cables and cards that are typically needed to support a virtualized machine or a non-virtualized machine, down to one or two wires. Instead of using physical cards, virtual I/O uses software to accomplish the same task. Wachovia has been working with several vendors to implement virtual I/O in its data centers, including Scalent of Palo Alto, Calif. One of the benefits of the Scalent technology, says Hall, is that it is agnostic of hardware suppliers, allowing Wachovia to maintain a neutral position. In tests, Hall's group found the virtual technology could increase I/O performance by 300%.

"With the advanced computing farms and processor arrays we want to put into our data centers, if you only have two wires going to every box, you can put 60 blades inside of a chassis and not be concerned that the number of cables are going to be so great it causes air flow problems or a problem in swapping out a cable if a connection goes bad," says Hall.

The benefits of virtual I/O technology in combination with processor arrays include the ability to troubleshoot or replace or upgrade blades without having to bring down the entire chassis - achieving the goal of high availability by default. "There's an upgrading benefit, there's a repair/troubleshooting benefit, and by simplifying the chassis design to only contain power and management, the chassis become cheaper and easier to inventory," adds Hall.