После вставки флешки нужно понять, как она определилась. Можно использовать один из вариантов
# rmformat Looking for devices... 1. Logical Node: /dev/rdsk/c3t1d0p0 Physical Node: /pci@0,0/pci8086,2829@d/cdrom@1,0 Connected Device: VBOX CD-ROM 1.0 Device Type: DVD Reader Bus: <Unknown> Size: <Unknown> Label: <Unknown> Access permissions: <Unknown> 2. Logical Node: /dev/rdsk/c4t0d0p0 Physical Node: /pci@0,0/pci106b,3f@6/storage@2/disk@0,0 Connected Device: USB FLASH DRIVE PMAP Device Type: Removable Bus: USB Size: 3.9 GB Label: <Unknown> Access permissions: Medium is not write protected.