This is something that l always forget to add the first time l deploy my rails applications that run on Apache + Passenger.

namespace :deploy do
  desc "Restarting mod_rails with restart.txt"
  task :restart, :roles => :app, :except => { :no_release => true } do
    run "touch #{current_path}/tmp/restart.txt"

  [:start, :stop].each do |t|
    desc "#{t} task is a no-op with mod_rails"
    task t, :roles => :app do ; end

This will tell Capistrano to restart the server the passenger way by touching the restart.txt file in the tmp dir rather then trying to restart using mongrel. Lets hope l don't forget next time