[Dovecot] mdbox + gzip and rsync

[Jean-Daniel Beaubien]

Hi,

After reading the following paragraph from the dovecot doc, I've been
wondering how it would affect rsync (when combined with gzip):

"Expunging a message only decreases the message's refcount. The space is
later freed in "purge" step. This is typically done in a nightly cronjob
when there's less disk I/O activity. The purging first finds all files that
have refcount=0 mails. Then it goes through each file and copies the
refcount>0 mails to other mdbox files (to the same files as where newly
saved messages would also go), updates the map index and finally deletes
the original file. So there is never any overwriting or file truncation."

How will the mailbox files (m.X) files be modified when I move or delete
emails using mdbox+gzip. Will the resulting gzipped mdbox files be
rsync-able or will they need a full re-upload?

If I plan on using rsync for backups, am I better off not using the gzip
feature (if i can spare the extra storage)???

Thanks,

-JD