I had one of my EC2 instances (Ubuntu 14.04) lock up on Monday morning.  I use it to run a Ruby on Rails app and to do a handful of ETL jobs.  The website wasn&#x27;t able to load and I wasn&#x27;t able to SSH into the box.  So, I went into the AWS console and rebooted the instance.  This has happened 3 times in the last 6 months.  It looks like the CPU spikes up to almost 100% around the same time when the instance locks up.<p>I&#x27;d love to be able to identify the root cause of the instance locking up.  It seems like this article is more about the commands you&#x27;d run to assess the health of an active&#x2F;working EC2 instance and not one that you&#x27;re unable to SSH into.  Any idea on how to identify the problem with my EC2 instance?