Just a note of caution: sync != backup. When I was younger and dumber, I had my own rsync cron script to do a nightly sync of my documents to a remote server. One day I noticed files were gone from my local drive; I think there were block corruptions on the disk itself, and the files were dropped from the filesystem, or something like that. The nightly rsync propagated the deletions to the remote "backup."

D'argh.

Musing: There's a step further along the spectrum that echoes the relationship, where where "backup" != "backup that resists malware".

In other words, a backup can be degraded into a sync-to-nothing situation if the client logic is untrustworthy.