When rerunning a failed backup, I end up seeing the following log message for files that were already backed up:
Apr 1, 2020 12:30 PM: Checking file for changes [filename here], new: True, timestamp changed: True, size changed: True, metadatachanged: True, 03/27/2020 04:11:59 vs 01/01/0001 00:00:00
There is one of these log messages for every file.
Then the backup starts inspecting the blocks from the already-backed-up file, all of which are already present in the backup target, and skips each block one at a time. I imagine this process would go a lot faster if the metadata for each file in the database was accurate, letting Duplicati skip processing the file outright.
Why is this metadata inaccurate, and is there anything I can do to fix it so that it is accurate in the future? I’m backing up terabytes of data and only a small amount is expected to change each night, so Duplicati is spending a lot of time processing files that it does not seem to need to process.
Details: I’m running Duplicati 2.0.5.1_beta_2020-01-18 using Docker on a Synology NAS and mounting the volume that I’m backing up as a volume in the Docker container.