Cloud Sync behavior - changed files only or all files?

TrueNAS General
1

I have a weekly cloud sync task configured for Backblaze B2, set to “SYNC.” My expectation is that this should only need to sync files that have have been changed/added/deleted, but it seems to be uploading all files every time it runs (which is around 3TB). Is this expected behavior? I’m used to working with rsync which works off of a delta between the systems.

2

Solved my own issue - I was SYNCing directories that I use with Resilio Sync, and not properly --exclude-ing the .sync directories in my jobs. SO much faster now.