Why does rsync copy all files and not just the ones that have changed?

Question

linux

I copy the test directory to the mounted WebDAV drive:

rsync -r -t -v -z -h  --progress  --delete --ignore-errors  /home/test   /mnt/disk/test

Everything is fine, everything is copied completely.
I run it again - it says there is nothing to copy. Also correct.
I change any file, I launch it again. Again correct - copies only the changed file.
After a couple of weeks (I can’t say for sure, but I noticed this several times) I start it - it copies everything again, although I shouldn’t copy anything at all, tk. there were no changes.
Maybe there is some kind of time limit when even an unmodified file is considered obsolete, so everything is copied again? Or what else could be the issue?

Answer 1

option "-c" - skip based on checksum, not modification time and size