Attention SSD users: if your temp directory isn't ram-backed, Duplicati will prematurely wear your SSD

[ts678]

I finally found the post that I was trying to recall in How can I speed up local backups?

@kenkendk

Duplicati always creates temporary files, and then copies these into the destination. This approach ensures that any half-done stuff does not end up at the destination.

Store temporary files in memory #2816 in 2017 talks about the non-seekable streams.

2014 comments probably predate Duplicati 2, but possibly some of the ideas still hold:

Attempt to avoid temp files if the backend supports streaming #181

The problem with this is handling retries, as the retry has to roll back the entire state and re-produce the volume.

If system disk is SSD and backups are large, Duplicati’s default options will cause write-wear #1032

This refers to unnecessary writes on SSDs where a system can write to a non-SSD location. If all you have is an SSD, you can reduce temp writes by disabling the upload asynchronously option.

–synchronous-upload is now the documented option. Anyone care to test if it will reduce writes and speed?