State Street has six major data centers in the United States, Europe and Asia, including three backup facilities. The company is building out its initial private cloud services from a disaster recovery facility in Massachusetts.

State Street had virtualized about 65% of its environment even before the private cloud project, but virtualization alone won't create what Perretta considers to be a cloud. New tools for provisioning, change control, load balancing, a common framework and various types of instrumentation to enable multi-tenant infrastructures are all part of the mix, he says. "Running on a very lean technology stack," State Street can deploy new in five minutes, he says.

State Street partitioned off part of its data center for "massive racks of commodity servers" that can be treated as a single entity, providing cloud services and virtual desktops.

State Street runs hundreds of applications across pretty much every major type of server: mainframes, Server, Unix and Linux. For its first cloud project, State Street is moving numerous workloads from high-end Unix servers to Linux. Although State Street is a VMware customer, Perretta says the company is emphasizing open source virtualization tools for this project. "We are as open as we can go," he says.

The first production applications -- targeted at State Street's external customers -- will be running on the Linux-based cloud this summer, he said. While Linux is the initial focus, State Street's cloud project won't be devoted entirely to open source. "Over time, we'll have a .NET cloud," Perretta said.