How Not to Build a Cloud

from CIO.com:

>>1. Don't centralize too much

Using IT services concentrated in data centers is the whole point of cloud computing and virtualization. But keep your eye on end user response times, says Vince DiMemmo, general manager of cloud and IT services at Equinix, which essentially provides the platform and infrastructure services on which other companies build their own. Customers include Verizon, AT&T, Japan Telecom, MCI, Comcast and YouTube, among others.

The lag between when a user presses a key and the response from a server that could be anywhere in the world could spell life or death for cloud computing projects, he says.

"If the user experience isn't fast enough, VDI services won't be accepted, just as SaaS wouldn't be," Bowker says.

Equinix spreads user access nodes around the edge of its network—close to concentrations of end users. "We cut down the physical distance between the network and the end user—even inside the building if we can connect directly," he says. "Every hop is a piece of equipment that contributes its own network latency and extra response time, even if it's only microseconds, if you add that to every packet for every node, it adds up."