Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for storing data are disclosed. In some implementations, visual representations of files are generated for presentation in a backup user interface. The visual representations are generated from sparse file system metadata stored on the computing device, thus allowing faster navigating of the backup user interface. During a restore operation, the metadata can be used to retrieve the items from their physical storage locations. In some implementations, when the storage capacity of a backup storage device exceeds a threshold, the data for the N oldest backups are replaced with sparse file system metadata, which can be used to generate visual representations for presentation in the backup user interface.