title: rsync code will run, but not in cron
body: <p>I have a web server (odin) and a backup server (jofur). On jofur, I can run the following code to rsync my web directories (via key authentication) from odin to jofur: </p>
  
  <pre><code>rsync -avz -e ssh backups@odin.mydomain.net:/home/backups /home/myuser/odin
  </code></pre>
  
  <p>If I enter this into the command line, everything rsyncs perfectly: </p>
  
  <pre><code>myuser@jofur:~$ rsync -avz -e ssh backups@odin.mydomain.net:/home/backups /home/myuser/odin
  
  receiving incremental file list
  
  sent 23 bytes  received 1921 bytes  1296.00 bytes/sec
  total size is 349557271  speedup is 179813.41
  </code></pre>
  
  <p>I want this to run every morning, so I edited my crontab to read this: </p>
  
  <pre><code>0 4 * * * rsync -avz -e ssh backups@odin.mydomain.net:/home/backups /home/myuser/odin
  </code></pre>
  
  <p>This doesn't work. The following message is deposited in /var/mail/myuser: </p>
  
  <blockquote>
    <p>Could not create directory '/home/myuser/.ssh'.
    Host key verification failed.
    rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
    rsync error: unexplained error (code 255) at io.c(605) [Receiver=3.0.9]</p>
  </blockquote>
  
  <p>I'm not sure what this error means. I'm wary of futzing blindly with permissions because I don't want to leave any backdoors open. Any suggestions? </p>