create physical volume from multipath raid system

I currently want to mount an existing raid system. The rack is connected via multipath. With the command multipath -ll all racks are correctly shown and the mapper are present under /dev. My first attempt was to create a physical volume from the mapper pvcreate /dev/mapper/raid However I got an unexpected return: Can't initialize physical volume "/dev/mapper/raid" of volume group "vgRAID" without -ff /dev/mapper/raid: physical volume not initialized. Am I missing something? It seems that volume group already exist. But as far as I remember I had to first create physical, then group and finally logical volumes. I don't want to use -ff as I doubt it will overwrite my filesystem.