Day 17. 10. 2023 7:46, Jean-Daniel Dupas <jddupas@xooloo.com> wrote:
If you are using Ubuntu, OpenZFS is readily available, and support deduplication natively. Else it is also available on other platforms, but may require more setup.
Filesystems does not have deduplication effective for emails. They mostly use block based deduplication, which does not work when the same attachment in second body is shifted even one byte, like when any header value is longer/shorter.
Deduplication using rolling hash (rsync) is better but still different clients can encode same part in different ways.
Even dovecot SIS is not very sophisticated in this, but it is better than block based deduplication.
Good deduplication can lower storage to almost 1/3 of full email bodies.
-- Filip Hanes