Visualized: America's Backup Drive

The official archive of the federal government has a big job: figuring out which parts of the 97.4-terabyte collection to try to preserve forever. As always, a picture makes things a lot easier.

THE MOMENT A program developed by computer scientists at the Texas Advanced Computing Center for the National Archives and Records Administration (NARA) visualizes the status of 12,000 files in a test data set. Each box represents a directory within the file system (those holding more data are larger), and colors reveal the risk that different sectors of data will become obsolete: green indicates low risk, blue shows medium risk, and red marks high risk. This latter category might include, for example, files created with outdated versions of word processing programs. Black and white areas delineate unknown file types and risk levels, respectively. Such visualizations will allow digital archivists at NARA—which maintains the records of all federal agencies—to prioritize files in their 97.4-terabyte electronic collection for preservation.