Last year I bought an M-Disc drive and a bunch of M-Discs and burnt all my files in Nextcloud to them as a backup.

It's a new year, I want to take any files added or modified in 2025 to burn a new disc.

I can work out how to get all files with a modified date in 2025, the problem is that if a file was moved into Nextcloud but wasn't changed, the modified date doesn't change. So I will miss files that someone has moved into Nextcloud without changing if the modified date is before 2025.

I can't use created date as literally all the files have a created date 1 Jan 2025 or later as the created date is when they synced from the server.

Normally I'd rsync to find changes but the current copy is spread across like 10 M-Discs, and reading each of those 100GB discs at CD reading speeds is going to be painful.

Does anyone have a better idea?

Edit: In case anyone is finding this later, I didn't get a better plan other than planning ahead. I copied each disc onto my hard drive (into a folder "Old replica"), copied the current state into a different directory ("New replica"), and ran Czkawka to remove files from "New replica" that are duplicates of files in "Old replica". And also used the Czkawka setting to delete empty directories once I deleted all those files.

What was left in "New replica" I burnt to disc, then Rsynced these back into the "Old replica" which I have for now left on my hard drive. Maybe if I run out of space I'll consider saving hashes or something for comparing, but for now this is just an extra copy I am storing because I didn't find a better way 🤷