I have a 750Mb external hard disk that I use for temporary backups, moving stuff from system to system, etc. I has both eSata and USB interfaces. Yesterday I tried to use it to copy some files off my linux based WD NAS. I couldn't mount it:- root@backup# mount -n -t ext3 /dev/sdc1 /usbdisk mount: Mounting /dev/sdc1 on /usbdisk failed: Invalid argument (adding/removing the -n or -t options made no difference) Running fdisk on the drive showed the following:- Disk /dev/sdc: 750.1 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdc1 1 91201 732572001 83 Linux So I re-partitioned the disk with fdisk and recreated the file system with mke2fs. Now fdisk -l reports:- Disk /dev/sdc: 750.1 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdc1 1 91201 732572001 83 Linux Which is identical to what it reported before. However the disk now mounts successfully! root@backup# mount -n -t ext3 /dev/sdc1 /usbdisk root@backup# So what's different? I guess it must be something to do with the file system created by mke2fs. -- Chris Green