Well actually it is a 16GB micro SD card in an USB adapter. It works properly on another computer with win7 and I used it for ubuntu with an arm sbc too. I made it fat32 under freebsd with sade, but I cannot mount it. I checked on win7 and formatted it, but even after that I cannot mount it on freebsd. I did geom disk list and it is called da0. When I do mount /dev/da0 ./usb I got "mount /dev/da0: No such file or directory" still I can see it with ls -a /dev. Any idea how to fix this?