title: Tasks not executed by the Compute Nodes in Ubuntu CfnCluster image
body: <p>I'm trying to use CfnCluster 1.2.1 for GPU computing and I'm using a custom AMI based on the Ubuntu 14.04 CfnCluster AMI.</p>
  
  <p>Everything is created correctly in the CloudFormation console, although when I submit a new test task to Oracle Grid Engine using qsub from the Master Server, it never gets executed from the queue according to qstat. It stays always in status "qw" and never enters state "r".</p>
  
  <p>It seems to work fine with the Amazon Linux AMI (using user ec2-user instead of ubuntu) and the exact same configuration. Also, the master instance announces the number of remaining tasks to the cluster as a metric, and new compute instances are auto-scaled as a result.</p>
  
  <p>What mechanisms does CfnCluster or Oracle Grid Engine provide to further debug this? I took a look at the log files, but didn't find anything relevant. What could be the cause for this behavior?</p>
  
  <p>Thank you,</p>
  
  <p>Diego</p>