Hi Christophe, you asked for it: This patch checks whether the mapname returned by dm_task_get_name is not zero-sized. So NULL is returned always for an invalid mapname. Cheers, Hannes -- Dr. Hannes Reinecke hare@suse.de SuSE Linux Products GmbH S390 & zSeries Maxfeldstraße 5 +49 911 74053 688 90409 Nürnberg http://www.suse.de