I/O size (minimum/optimal): 512 bytes / 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I have got an external hard disk TOSHIBA 1TB USB 3, the permission is always READ ONLY.įdisk -l (output) : Disk /dev/sda: 500.1 GB, 500107862016 bytesĢ55 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors