Cron <root at backup1> /usr/local/bin/rsnapshot -c /usr/local/etc/rsnapshot_desktops.conf daily

[root]

cp: /storage/backups/desktops/daily.0/luna/home/vipuls/Desktop/luna-fusion/dougal/notebooks/nb is a socket (not copied).
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@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
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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 a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
19:b5:86:17:86:bd:41:88:eb:49:3a:81:48:7a:b5:2d.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending RSA key in /root/.ssh/known_hosts:9
RSA host key for lena.auton.cs.cmu.edu has changed and you have requested strict checking.
Host key verification failed.
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
rsync error: error in rsync protocol data stream (code 12) at io.c(226) [Receiver=3.1.1]
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rsnapshot encountered an error! The program was invoked with these options:
/usr/local/bin/rsnapshot -c /usr/local/etc/rsnapshot_desktops.conf daily 
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ERROR: /usr/bin/rsync returned 12 while processing backup at lena.auton.cs.cmu.edu:/home/benediktb/