title: jenkins 1.5.20 master goes offline with too low temp space
body: <p>I am using jenkins 1.520, i have 500mb in /tmp on linux (RHEL6 host), 500mb is plenty of space for our current build size and number of projects, how can i make this message go away and have my master node be online? </p>
  
  <p>I looked around for bugs that apply to this version, did not find any. I tried previous suggestions found in stackoverflow, do not seem to work or simply do not apply.</p>
  
  <pre><code>df -h
  Filesystem            Size  Used Avail Use% Mounted on
  /
  /dev/mapper/vg00-tmp  504M   23M  456M   5% /tmp
  </code></pre>
  
  <p>..thanks...</p>