问redis- capistrano3 :部署后如何启动-停止-重启rails4 -capistrano3？

EN

 service redis-server restart

%w[start stop restart].each do |command|
  desc "#{command} Redis server."
    task command do
      on roles(:app) do
       execute "service redis-server #{command}"
      end
    end
end

 DEBUG [8410afb7] Command: service redis-server restart
 DEBUG [8410afb7]   Stopping redis-server:
 DEBUG [8410afb7]   redis-server.
 DEBUG [8410afb7]   Starting redis-server:
 DEBUG [8410afb7]   touch:
 DEBUG [8410afb7]   cannot touch ‘/var/run/redis/redis-server.pid’:  
 Permission denied