The Wikimedia Foundation, which operates Wikipedia, is making an Equinix data center in Ashburn, Virginia, its primary data center, leaving the formerly primary site in the Tampa, Florida, area for backup.

The foundation has migrated most of its main infrastructure to the Ashburn data center over the past several months, according to an update on its technical operations posted on the Wikimedia Tech Blog. The Ashburn data center is currently serving about 90% of all of its traffic, and the rest will be migrated over the next several weeks.

“The Technical Operations team continued to work on completing the outstanding migration tasks, and to ready our Ashburn infrastructure for the big switchover day, i.e., the complete transition from the Tampa data center to the one in Ashburn, on the week of January 22, 2013,” Wikimedia engineers wrote in the blog post.

MediaWiki application, menchached and database systems were running exclusively out of Tampa as of 10 January.

In addition to the Tampa and Ashburn locations, Wikimedia has data centers in San Francisco and Amsterdam, Jay Walsh, a foundation spokesman, wrote in an email.

Once the transition is complete, Wikimedia’s web properties will have assurance of a hot standby data center that could pick up the load if one of its main data centers experiences a prolonged outage, Wikimedia engineers wrote in the blog post.

In August 2012, cut of a fiber-optic cable near the Tampa data center brought many of the foundation’s web properties down. The outage lasted longer than three hours.

In another downtime example, Wikipedia (Wikimedia’s popular user-edited online encyclopedia) became inaccessible to European users in March 2010. That outage happened when Wikimedia’s servers housed in an EvoSwitch data center in Amsterdam had shut themselves down because temperature inside the data center had unexpectedly risen.