Git annex will keep track of where files are for you.

You could make a text file of all the directories/files, name it according to the drive name, and then you could search the text files or just scroll through it.

https://stackoverflow.com/questions/23808798/how-can-i-export-a-recursive-directory-file-listing-to-a-text-file-in-linux-ba

Not sure if it’s more suitable than what’s been suggested already, but I use Virtual Volumes View, an open source program to log/index my (disconnected) external drives and older hard drives.

I then keep the database/catalogue in a shared location I can check from my desktop/laptop.

Save a list of all the files full paths, then run that file through fzf https://github.com/junegunn/fzf

Strange that anyone,didn’t recommend gui app fsearch https://github.com/cboxdoerfer/fsearch

You could maybe do some tricks with one of the variations of locate - such as mlocate or locate. There are options for the updatedb to index specific paths and store in the specified database. If you store a separate db per drive, a bit of scripting to loop through all DBs would let you search them all.

mlocate, plocate, slocate

Mount the drive, run updatedb, then unmount the db when that finishes. Then use the locate command.

https://plocate.sesse.net/

I’m pretty sure tag spaces can do this if you’re open to going that route.

To index the contents of the drives, you can redirect the output of the find command to a file. For example, find /path/to/your/drive -type f > drive_index.txt will create a file named drive_index.txt containing a list of all the files in the drive.

Then place all the file list in the same folder and grep that folder to find which drive contains the file.

The hard drive that is disconnected

Not being facetious but you could write your own tool. It might take a minute at first but then it would be yours and be totes worth it.