rsync & ssh

[amoser at sewanee.edu]

A few months ago I set up (relying in part on helpful
instructions at
http://www.math.ohio-state.edu/%7Eccunning/osx-backup.html)
a rudimentary backup scheme from my powerbook to an iMac: in
the wee hours of the morning the powerbook would connect to
the imac via ssh, using public key authentication, and would
then use rsync to synchronize some key folders. This felt
like quite an accomplishment, since I'm a bit of a unix
idiot, but I've recently noticed that the ssh connection no
longer works -- any attempt to ssh from the powerbook to the
imac yields the following msg:

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now
(man-in-the-middle attack)!
It is also possible that the RSA host key has just been
changed.
The fingerprint for the RSA key sent by the remote host is
5f:6a:9d:b6:63:b1:3b:5f:65:91:ee:62:44:e9:3d:d7.
Please contact your system administrator.
Add correct host key in /var/root/.ssh/known_hosts to get
rid of this message.
Offending key in /var/root/.ssh/known_hosts:1
RSA host key for 10.0.1.2 has changed and you have requested
strict checking.
Host key verification failed.

Keeping in mind that my knowledge of unix (and the technical
terms associated with it) is woefully inadequate, any
suggestions about what I need to do to get the ssh and
backup scheme up and running again? (I think I changed the
admin password on the imac recently, so that may account for
the problem, but I still don't know quite what to do to
solve it.)

Also, it seems like there just aren't many unix resources
(books, websites, etc.) geared toward showing people who
aren't unix gurus but are competent with computers how they
can leverage the unix commands inn Mac OS X to accomplish
useful things like backups. (Man pages tend to be pretty
unhelpful in this respect.) Any thoughts on this score?

Thanks!



Andrew Moser
Department of Philosophy
University of the South