Weathermapcacti

pouvez vous m'aide a ressoudre ces messages d'erreur dans cacti:
04/23/2015 04:10:08 PM - WEATHERMAP: Poller[0] WARNING: Output directory (/usr/share/cacti/site/plugins/weathermap/output) isn't writable (tried to create '/usr/share/cacti/site/plugins/weathermap/output/weathermap.permissions.test'). No maps created. You probably need to make it writable by the poller process (like you did with the RRA directory) [WMPOLL06]