This is how to wipe a disk via Linux shell:
$> sudo shred -v -n2 -z /dev/sdc
The command above erases all data on the device /dev/sdc and overrides the data 2 times. Finally every bit is overridden by zeros. So in sum it takes 3 iterations to wipe a disk via Linux shell.
- n specifies the number of iterations taken place to override the data with random numbers
- z results in every bit being overwritten by zeros to mask shredding
Further information on wipe a disk via Linux shell:
Can be found under https://linux.die.net/man/1/shred .