I have several (a lot of) external hard-disks, and it's impractical (and unnecessary) to have all connected to my computer simultaneously. It would however be great to maintain a database on my computer, so I quickly could find the correct external disk for a particular file or directory. As the drives are filled-up, their content is more or less static (so it would usually be enough to index them only once).

Apart from the ID/Name of the external drive, it would be great if the database didn't only contain file-names, but also size and modification date - to help identify doublets and/or newest version. The path - and especially the parent directory - would also help identifying doublets. Generation of a check-sum (something like what's used in GIT) would further help identify multiple occurrences of the same file on several disks.

So, are there any good programs for indexing and creating databases of files/directories - especially suited for off-line media and/or for identifying multiple occurrences of the same file?