Creating a File System on an external drive.

mkfs.ext3 -j /dev/sdb1

Got sdb1 from fdisk -l or dmesg (from when the disk is enumerated)

(This probably wipes the disk)

Then you can mount it

mount -t ext3 /dev/sdb1 /mnt/usb-backup (make sure usb-backup exists)

I carried out the above when I was trying to mount an external hard disk and getting the following error:

mount: wrong fs type, bad option, bad superblock on ext3 partition....