I've been trying to find if the -e option is necessary? Am I not ssh-ing without it by simply doing user@server when running rsync?
Rsync -e option to ssh
ssh;rsync
Assuming you're not needing to consider the rsync protocol itself, this depends on the compilation options used for your version of rsync.It used to be the case that rsync used the rsh protocol by default (unless the build-time default had been changed), but the build-time default changed to ssh in 2004.If you're in doubt, start the rsync process transferring a relatively large file (or collection of files), and in another terminal run ps -ef | grep [r]sync. This will show you whether or not you're using ssh for a transport. Here's an example from one of my servers, which clearly shows the ssh transport:root     28057 27173  1 09:48 pts/4    00:00:00 rsync -avHP --dry-run /home roaima@otherserver:root     28058 28057  0 09:48 pts/4    00:00:00 ssh -l roaima otherserver rsync --server -vnlHogDtpre.iLsfx --partial . .Finally, be aware that the compilation default can be overridden with the RSYNC_RSH environment variable. (See the man page for further details.)