Double File
Examine your file collection: what's backed up; disk usage.
On the surface, Double File may look like WinDirStat (from which it borrows code) or similar graphical drive utilization utilities: e.g. the second assembly 'Volume Treemap'. However, Double File is project-based: it saves file checksums in directory listings you store locally. It facilitates planning and transitioning between computers and operating systems: snapshot your drive and safely archive it.
Listings can be searched when volumes are off site. Can read any volume mounted in Windows Explorer, including Linux and Mac volumes. Supports long path names.