title: nginx server cannot restart using service nginx start
body: <p>This is my error.log</p>
  
  <pre><code>2016/07/01 07:38:17 [emerg] 30759#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 07:48:02 [emerg] 30806#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 07:48:44 [emerg] 30832#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 08:07:36 [emerg] 30913#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 08:07:44 [emerg] 30939#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 08:07:49 [emerg] 30964#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 08:13:54 [emerg] 31138#0: getpwnam("nginx") failed in /etc/nginx/nginx.conf:5
  2016/07/01 09:52:49 [emerg] 31735#0: getpwnam("nginx") failed
  </code></pre>
  
  <p>And this is my nginx.conf</p>
  
  <pre><code>worker_processes auto;
  error_log /var/log/nginx/error.log;
  pid /run/nginx.pid;
  
  events {
      worker_connections 1024;
  }
  
  http {
      log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                        '$status $body_bytes_sent "$http_referer" '
                        '"$http_user_agent" "$http_x_forwarded_for"';
  
      access_log  /var/log/nginx/access.log  main;
  
      sendfile            on;
      tcp_nopush          on;
      tcp_nodelay         on;
      keepalive_timeout   65;
      types_hash_max_size 2048;
  
      include             /etc/nginx/mime.types;
      default_type        application/octet-stream;
      include /etc/nginx/conf.d/*.conf;
      server {
      listen       80 default_server;
      listen       [::]:80 default_server;
          server_name  _;
          root         /usr/share/nginx/html;
          include /etc/nginx/default.d/*.conf;
          location / {
          }
      error_page 404 /404.html;
              location = /40x.html {
          }
  
      error_page 500 502 503 504 /50x.html;
              location = /50x.html {
          }
      }
  }
  </code></pre>