How can I keep a reference copy of the directory tree of a disconnected external hard drive?

Question

I have about 60 external hard drives, and am looking for a way to document what's on them in a user-friendly way (rather than just outputting the structure in text form).

Dream scenario: I have a copy of the full directory tree of each drive, that I can keep on my computer and navigate in Finder. All the files are there but are truncated to 0 bytes - just placeholders to give me a way to see filenames. Bonus points for preserving modified dates on the files.

(Sort of like how iCloud gives you a fake directory structure of stuff it has in the cloud that's available for local download, but isn't actually living locally at the moment. And to be clear all I want are the placeholders, not some way to have files magically sync when I click the placeholders like iCloud does.)

Also acceptable: A database with a vaguely Finder-like interface that lets me search, and navigate directory trees.

I'm on OS X and the drives are formatted HFS+

Answer 1

I use WhereIsIt to catalog my DVD-ROM backups. They don't have a Mac version, but AlternativeTo.net has a number of likely choices:

Alternatives to Where Is It? for Mac with any license