Despite the consolidation trend, some companies are continuing to branch out with their data centres for reasons including redundancy of the centralized data centre for backup, a more comprehensive disaster recovery plan and better uptime at regional offices.
Indeed, some companies actually prefer this approach, and experts say it makes sense for organizations such as those with branch employees who can act as IT technicians or firms with locations dispersed on different continents.
"The satellite data centre model is alive and well in companies that support multiple regional offices, such as banks, chain stores and insurance companies," said Charles King, a principal analyst at Pund-IT in the U.S. "The benefits are substantial for any industry where it's important and advisable to keep workers close to data and their IT infrastructure."
George Hamilton, an analyst at Yankee Group Research, said he's also in favour of satellite data centres in some instances.
"The advantage is leveraging existing space, rather than having to build additional data centre capacity," he said. "With virtualization, you can make the satellite data centres appear as one big data centre -- the users have no idea where the physical devices reside, nor do they care. It also builds in local redundancy -- unless the entire building is affected. You can also shut down one satellite data centre and have another pick up the functionality during technology refreshes and upgrades."
Three kinds of satellites
One type of satellite data centre is a "data room" on each floor. This was formerly known as an intermediate distribution frame (IDF) and is now commonly called a tenant technology room (TTR). Granted, these are not true data centres. However, the TTR of a large organization might be larger than an entire data centre in a small company.
A second type is a regional office with a local data centre that provides a subset of services, such as e-mail and document servers. Law firms are well known for having data centres at each office, serving just a few hundred employees.
A third is a data centre located in a different state from the main data centre entirely, usually to reduce constantly escalating utility costs. In this approach, the IT organization might be relocated to the remote data centre, with the home office staying in the original location.
Business continuity is key
In all cases, decentralizing can help organizations minimize the consequences of a catastrophe, said Steve Novak, CIO at Kirkland & Ellis in Chicago.
For some mission-critical applications, such as e-mail and instant messaging, the firm runs a data centre in each office that is redundant with the centralized data centre. "If we lose e-mail in the local office, we know the secondary server is available and vice versa," Novak said.
In the Kirkland & Ellis model, a 100-square-foot TTR on each office floor handles basic networking, a 1,000-square-foot satellite data centre handles mission-critical services such as e-mail, and a 10,000-square-foot global data centre in Chicago handles most companywide services.
That said, however, Kirkland & Ellis stores all documentation -- the intellectual capital that forms the lifeblood of the company -- in a centralized data centre where long-term redundancy is more important than uptime. The other option, which is less reliable, would be to store documentation in each regional office.
With a move to server virtualization, the firm is building a global data centre next year that will further unify data services but still not change the regional data centre strategy with regard to e-mail and instant messaging.