W3 Total Cache plugin doesn't work without setting 777 permission for w3tc-config directory
If you're using W3C Total Cache you should do :
chmod 777 wp-content/w3tc-configchmod 777 wp-content/cacherm -rf wp-content/cache/configrm -rf wp-content/cache/objectrm -rf wp-content/cache/dbrm -rf wp-content/cache/minifyrm -rf wp-content/cache/page_enhancedIn this case,Everytime when you clear cache then w3tc needs to regenerate a cache,So need write permission.