 <p>I assume you are running Ubuntu as production server. On your server you need to edit your <code>sudoers</code> file:</p> <p>First type <code>select-editor</code> and select nano (or another editor you feel confortable with)</p> <p>Then at the bottom of the file, before the <code>include</code> line, add this line: </p> <pre><code>%deployer ALL=(ALL)NOPASSWD:/path/to/your/unicorn_rails </code></pre> <p>You need to replace <code>deployer</code> by the user name you are using with capistrano, and to replace <code>/path/to/your/unicorn_rails</code> with its correct path. This will allow your deployer user to "sudo unicorn_rails" without being prompt for a password.</p> <p>Finally edit your <code>unicorn:start</code> capistrano task, and add <code>rvmsudo</code> ahead of your command line that start unicorn:</p> <pre><code>rvmsudo unicorn_rails -c config/unicorn/production.rb -D --env production </code></pre> <p>If it does not work you can try this instead</p> <pre><code>bundle exec sudo unicorn_rails -c config/unicorn/production.rb -D --env production </code></pre>