Mount My Stora Raid disk on SUSE

I have a My Stora 1 TB Raid storage NAS. I have 3x1 TB disks, the idea being that I can dismount one of the 2 in the NAS every now and then, stick it in a safe place as a backup, mount the 3rd disk instead and the My Stora will then reduplicate everything on it.

But as a real backup I would even like to be able to mount the 3rd disk directly on my Linux machine - if the My Stora hardware breaks down that way I can still get at all my files. I’m running SUSE 11.2, and when I plug in the disk and run fdisk -l I get the following:

Device Boot Start End Blocks Id System
/dev/sdf1 1 121577 976562500 fd Linux raid autodetect

When I try to use the partitioner to mount the disk (without reformatting it) it recognises the FS as Ext4, but then when I click on “Finish” I get the error message “It is not allowed to assign a mount point to a device with a nonexistent or unknown file system”.

Anyone know what to do?