I have a local PBS server which runs on the PVE. If i wanna implement a sync job to a offsite, pbs sync job will sync incremental per backup or will it try to copy full backup? (which is deduplicated on the main server)
The PBS has no knowledge of the dirty bitmap, it is needed when the VM is backed up, but once the backup is on the PBS, it doesn't need it. The backups are stored as chunks and the backups reference them. Multiple backups can reference the same chunks.
So the remote sync will sync new backup metadata and chunks that are not yet present on the target machine.