Unable to Mount External Hard Drive on LL 7.0

[stevef]

The error message you have quoted implies the disk may be formatted as ntfs.

With the drive attached, please run this command

Code:

sudo fdisk -l

This will show some information abut the disks attached to your system.
Please post back with the information it shows about the external disk.

Do you use this disk on multiple systems e.g. Windows or older Linux ?
Is there anything important on the external disk ?
If the contents are important, are they safely backed up somewhere ?