title: How to "undrain" slurm nodes in drain state
body: <p>Using <code>sinfo</code> it shows 3 nodes are in <code>drain</code> state,</p>
  <pre><code>PARTITION AVAIL  TIMELIMIT  NODES  STATE NODELIST
  all*         up   infinite      3  drain node[10,11,12]
  </code></pre>
  <p>Which command line should I use to <em>undrain</em> such nodes?</p>