cornbread,
I've noticed your posts on this over the past few days and it occurs to me. . .given that what you're wanting to do is open-source backup, as you have probably realized by now, the effective OSS backup requires you to have Zimbra services stopped. Since you don't want them stopped for longer than necessary, you might really want to break up the stages of your backup anyway. By this I mean do your rsync (or other file copy process) to a local hard drive, as most of
these methods do, restart Zimbra, and then (and ONLY then) back it up to the remote location. If you make the backup into a tar/compressed file, then you can use any methodology for ssh that can do ftp over ssh, which might make your scripting easier.
This will be significantly faster in terms of Zimbra downtime since the limiting factor will be HDD throughput rather than your net link throughput.
cheers,
Dan