I checked the archives and bug lists, and didn't see this. Or rather, I saw someone report it, but it was backrev and a "non-standard" release, so that was considered out of bounds. I'm running on Ubuntu Dapper Drake, and first experienced this problem trying to do rsync backups via backuppc. I wanted to do a "don't cross filesystem boundary" backup from / so I didn't have to explicitly exclude mount points (eg: NFS mounts, backup partition, USB drives, cdroms, /proc etc). Dapper's rsync is 2.6.6, so I upgraded to 2.6.9 just in case, and still see it. This is the problem reduced to the simplest form: sh-3.1# ./rsync --version rsync version 2.6.9 protocol version 29 sh-3.1# ./rsync -x / /zorilla/foo skipping directory /. Nothing is copied. rsync's device crossing detector seems to get confused about /, and refuses to traverse it if -x or --one-file-system is on. My workaround is to enumerate and exclude all mount points, but one day someone is going to mount something somewhere unusual, and even maybe end up with an infinitely recursive backup.