I am using deploying a Ruby on Rails app to a Linode VPS using Capistrano. I am using Unicorn as the application server and Nginx as the proxy. My problem is that I am not able
Actually, the error message has already told you why:
directory for pid=/home/deploy/apps/shared/pids/unicorn.pid not writable
So, does the directory /home/deploy/apps/shared/pids exist? If not, you should call mkdir to create it.
/home/deploy/apps/shared/pids
mkdir