[[!comment format=mdwn
 username="joey"
 subject="""comment 23"""
 date="2017-05-09T17:52:11Z"
 content="""
@mario, great question! (Not the best place for such a question, start a
thread on the forum next time..)

git-annex does use rsync when transferring files between ssh remotes.
Rsync normally goes over ssh, and it might be better to enable compression
at the ssh level. For example, I have "Compression yes" in `~/.ssh/config`

I think that the reason your annex-rsync-upload-options setting broke
it is that rsync needs --compress to be passed on to the other
rsync process (in the remote repository), and that is run via
git-annex-shell, which has a whitelist of options it will pass to rsync.
Passing arbitrary options to rsync could allow unwanted behavior
when git-annex-shell is being used as a security barrier. And --compress is
one of the options that both the rsync sender and receiver have to agree
on for the rsync protocol to work.

I have added a note to the man page about this limitation of what
the rsync-options settings can be used to do.
"""]]