I'm setting up an unattended rdiff-backup scheme and using Dean Gaudet's guide
as, well, a guide. On the same wiki I also found an article
that gave some instructions on how to modify that guide to use an alternate key. This supposedly fixes an issue whereby if you are logged onto the backup host and then ssh (from the shell) into one of the client machines as root, you end up invoking the rdiff-backup.
Reading the original guide some more, however, I see that it uses an ssh config alias to make the connection. Shouldn't this obviate the need for the alternate key? Am I missing something? Can someone explain this issue to me?