我是小白，第二次配置 rails 服务器，首先创建/修改了 nginx/conf.d/mo.conf，完全复制了 puma 官方提供的源代码（当然更改了路径）

upstream myapp(这里真的就只是“myapp”，没敢改成自己的appname) {
  server unix:///home/mo1.0/tmp/puma.sock;
}

server {
  listen 80;
  server_name myapp.com;

  # ~2 seconds is often enough for most folks to parse HTML/CSS and
  # retrieve needed images/icons/frames, connections are cheap in
  # nginx so increasing this is generally safe...
  keepalive_timeout 5;

  # path for static files
  root /home/mo1.0/public;
  access_log /home/mo1.0/log/nginx.access.log;
  error_log /home/mo1.0/log/nginx.error.log info;

  # this rewrites all the requests to the maintenance.html
  # page if it exists in the doc root. This is for capistrano's
  # disable web task
  if (-f $document_root/maintenance.html) {
    rewrite  ^(.*)$  /maintenance.html last;
    break;
  }

  location / {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;

    # If the file exists as a static file serve it directly without
    # running all the other rewite tests on it
    if (-f $request_filename) {
      break;
    }

    # check for index.html for directory index
    # if its there on the filesystem then rewite
    # the url to add /index.html to the end of it
    # and then break to send it to the next config rules.
    if (-f $request_filename/index.html) {
      rewrite (.*) $1/index.html break;
    }

    # this is the meat of the rack page caching config
    # it adds .html to the end of the url and then checks
    # the filesystem for that file. If it exists, then we
    # rewite the url to have explicit .html on the end
    # and then send it on its way to the next config rule.
    # if there is no file on the fs then it sets all the
    # necessary headers and proxies to our upstream pumas
    if (-f $request_filename.html) {
      rewrite (.*) $1.html break;
    }

    if (!-f $request_filename) {
      proxy_pass http://myapp;
      break;
    }
  }

  # Now this supposedly should work as it gets the filenames with querystrings that Rails provides.
  # BUT there's a chance it could break the ajax calls.
  location ~* \.(ico|css|gif|jpe?g|png|js)(\?[0-9]+)?$ {
     expires max;
     break;
  }

  # Error pages
  # error_page 500 502 503 504 /500.html;
  location = /500.html {
    root /home/mo1.0/public;
  }
}

然后是 config/puma.rb

threads 8,32
workers 3
preload_app!
on_worker_boot do
  ActiveSupport.on_load(:active_record) do
    ActiveRecord::Base.establish_connection
  end
end
bind 'unix:///home/mo1.0/tmp/puma.sock'
stdout_redirect '/home/mo1.0/log/stdout', '/home/mo1.0/log/stderr'
environment 'production'
daemonize
pidfile '/home/mo1.0/tmp/pids/puma.pid'
state_path '/home/mo1.0/tmp/pids/puma.state'

之后把 puma 跑起来后输入 ps aux，发现运行的进程没有 puma 直接访问 ip（lz 还不会配置域名），提示 502 bad gateway，说明 nginx 跑起来了，puma 跪了 服务器是 linode 的，还挺好使的，域名买了了.com 的只不过还没 DNS 解析呢，想先测试一下，结果就这样了

求帮忙 QUQ

解决方法：看 puma 的错误日志 === puma startup: 2015-05-19 17:04:50 +0800 === /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cli.rb:246:in initialize': No such file or directory - /home/mo1.0/tmp/pids/puma.pid (Errno::ENOENT) from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cli.rb:246:inopen' from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cli.rb:246:in write_pid' from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cli.rb:222:inwrite_state' from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cluster.rb:332:in run' from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/lib/puma/cli.rb:499:inrun' from /usr/local/rvm/gems/ruby-2.0.0-p643/gems/puma-2.9.0/bin/puma:10:in ' from /usr/local/rvm/gems/ruby-2.0.0-p643/bin/puma:23:inload' from /usr/local/rvm/gems/ruby-2.0.0-p643/bin/puma:23:in

' from /usr/local/rvm/gems/ruby-2.0.0-p643/bin/ruby_executable_hooks:15:ineval' from /usr/local/rvm/gems/ruby-2.0.0-p643/bin/ruby_executable_hooks:15:in `' 发现文件夹路径设置错误，修正后即可（puma 可以自动生成文件，但不会生成文件夹） 此外，如果去掉后台化代码后 puma 运行时是不能操控终端的，如果发现可以继续操作中断说明 puma 跪了