http {
  fastcgi_cache_path /var/nginx 
                     levels=1:2
                     keys_zone=mycache:10m 
                     inactive=1h 
                     max_size=4g;
  ...
location ~ \.php$ {
	fastcgi_cache mycache;
	fastcgi_cache_key $host$request_uri;
	fastcgi_cache_valid any 1h;
	fastcgi_cache_use_stale off;
...