B2 has now S3 compatible API

It’s possibly less hassle (but for what gains?) using New Feature — Bucket to Bucket Copies.

This all occurs without having to download or re-upload any data.

In addition to the third-party tools they mention, it seems to be in their own command line tool:

Add support for b2 copy file #586

I haven’t tried any of this two-day-old feature yet. If anyone wants to, feel free to give it a test.
Duplicati actually has two different S3 backends to use. Amazon’s and more recently MinIO’s:

image

Some supposedly “S3 compatible” storage is less than perfectly compatible with Amazon S3:

Problem using Oracle S3 compatible storage

‘s3 compatible’ storage does not work with Signature version 4 #3970

Some compatibility issues might be due to Amazon SDK, but I’ve heard no MinIO test results.