> Is there some other way to properly erase the disk so I can start from > scratch and lay down a new filesystem? Since neither gparted, not parted, nor fdisk seemed to be able to do the job, I used dd: dd if=/dev/zero of=/dev/sdc bs=8192 After that I used parted to create a new disk label, and then all was well. I was able to lay down new partitions without a problem.