But Google no longer uses GFS. Two years ago, the company moved its search to a new software foundation based on a revamped file system known as Colossus, and Urs Hölzle — the man who oversees Google’s worldwide network of data centers — tells Wired that Colossus now underpins virtually all of Google’s web services, from Gmail, Google Docs, and YouTube to the Google Cloud Storage service the company offers to third-party developers.