ShareThisRsync is a great open source utility. I've been using it for several years to redundantly backup our Lotus Domino server. I have a script that shuts down Domino, backs up the Notes including the notes.ini to a tar.gz file and then brings Domino back up. Later in the early morning hours another script runs in cron that uses Rsync to move the tar.gz file from the Domino server to another Linux server that's on our local area network. Yesterday while doing some more research to improve that Rsync script I came across a version of Rsync that's been written for Windows. It's called DeltaCopy. DeltaCopy is a really nice little program that runs as a service on a Windows computer and allows you a great GUI from which to backup your files.

In general terms, DeltaCopy is an open source, fast incremental backup program. Let's say you have to backup one file that is 500 MB every night. A normal file copy would copy the entire file even if a few bytes have changed. DeltaCopy, on the other hand, would only copy the part of file that has actually been modified. This reduces the data transfer to just a small fraction of 500 MB saving time and network bandwidth. In technical terms, DeltaCopy is a "Windows Friendly" wrapper around the Rsync program, currently maintained by Wayne Davison. "rsync" is primarily designed for Unix/Linux/BSD systems. Although ports are available for Windows, they typically require downloading Cygwin libraries and manual configuration.