> I don't use a DB, which is a nice idea to add OP did it more professionally than I did though: with a "real" SQL DB. I just have strings (from scripts) with

> I don't use a DB, which is a nice idea to add OP did it more professionally than I did though: with a "real" SQL DB. I just have strings (from scripts) with filesize+hash but it's still a DB and it's versioned (in Git). > But: how do you make sure that the last remaining original doesn't "loose the war" ...? So I'm very cautious when I tag files for deletion: for example a copy of all the tagged files is first sent to a directory where I do a review before confirming it's to be always deleted. If I'm not cautious, I can potentially tag for deletion a file that I want to keep and then I'm kinda toast. Now as to not lose the last file due to de-duplication: I do have lots and lots of backups (online/on-site [several computers], online/off-site [dedicated servers], offline/on-site [HDDs/SSDs on shelves, DVDs and probably soon BluRay discs] and offline/off-site [family members' house, wife's SME, etc.]). I mean, in a way backups are what prompted me to go the "forever delete + de-deduplicate". Which is a bit ironic but... I don't care too much if some backup somewhere contains a file I want to be deleted / de-duplicated but which is not. What's important to me is that should I need to reach for all the files on the backup I can then quickly delete all the files I already tagged for deletion.