I tried some backup software (of the rdiff variety, not the amanda variety) last year when I set up a small backup server for friends and family. Obnam and bup

I tried some backup software (of the rdiff variety, not the amanda variety) last year when I set up a small backup server for friends and family. Obnam and bup seemed to work mostly the way I wanted to but obnam was by far the most mature tool, so this is what I chose in the end. On the plus side, it provides both push and pull modes. Encryption and expiration works. The minus points are no Windows support, and some horror stories about performance. Apparently it can slow to a crawl with many files. I haven't run into that problem despite hundreds of gig in the backup set, but most are large files. On the whole it's been very stable and unobtrusive during the time I've used it, but I haven't used it in anger yet. So a careful recommendation for obnam from me.