Back In Time - looks quite good, it offers about what TimeMachine does. Ok, Linux-typically a bunch of options and selections have been added and simply / as a source for the backup does not work, but well, if you manually include the relevant directories (and remember to update the selection occasionally when changes are made), you can actually do something with it. The basis is rsync with hardlinks, so in the end really usable backups, because you can also manually restore them if necessary. What I haven't tried yet is what happens when you back up to removable media and they are not present. But there it also failed with faubackup. UPDATE: works quite well with removable media, it does issue an hourly message if the drive is not present, but it recognizes it cleanly and skips the backup run then. It would be nice to have an "automatically back up when the drive appears".