I'm running Novell SLED 10.1 and need to back up approximately 40GB of data to jump over to Ubuntu 8.10. I cannot store data on my external HD; I get access denied errors. I have tried reformatting and repartitioning the drive, and I still cannot write to it, and there is still data there even after reformatting.

The drive will mount, but again, I cannot write to it. I have tried chmod 755 /dev/sdb1 as well as chmod 755 /media/SimpleDrive. I currently have two ext2 partitions, on which the Get Started with Windows and Mac files still exist and to which I still cannot write. Any help here would be appreciated...
I've used cfdisk and fdisk to repartition. mkfs won't create a filesystem on a mounted drive. I can't afford to lose the data on my internal HD, either.

this has to be done as root.check and see if you have gparted.this you can do through your yast program I think suse uses. then it will ask you for your password then go to the drive and do it. any way sudo or su then password in a terminal. type cfdisk /dev/your device sdX or hdX what ever. or you can down load live cd puppy linux and boot it up and use gparted.
you will find suse is set up so you jump through some hoops to get things done as root. this is to protect your system.

AFAIK, that's how it's supposed to be. You need to umount it first to use mkfs.
Create a partition, write a file system to it, and then mount it:
And see what happens...

and like sycamorex said above you need to umount /dev/your hard drive.