I use Rsync for Windows. Once the initial backup is complete Rsync backs up only those portions of the file that have changed - ideal for WAN / Internet based backups. Plus the software is free. The implementation I use is called DeltaCopy. I replicate about 50 gigs of data via a 512 kbps uplink every night...takes about 90 minutes. This includes two Exchange databases and a few small SQL databases. Again, only the changes to the files are moved. Rsync originated in the Unix world and as with many Unix utilities is a command line program with all kinds of parameters - but it's no more complicated than RoboCopy. DeltaCopy wraps Rsync in a simple GUI. http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp[^]

I'm both a sysadmin and a programmer. I make multiple backups of all of the data on the server nightly. Two local disk based backups (not on the server), one online backup to a commercial service and one online backup to a server I own at a colo facility. I keep seven full backups on the colo'd server. I love rsync. I'm in the process of setting up another server to use for backups for my clients. Will be able to charge them less than the fancy services such as Mozy Pro and still make a decent profit.