sorry miss info about dd command
Without quotes the command to blank a drive is "dd if=/dev/urandom of=/dev/sda"
If the drive you want to blank is sdb then substitute sdb for sda. In the original post I reversed the syntax by mistake.
if (means the file or device you are writing from) "if" just stands for input file
of (means the device or file that you are writing the input to)
dead simple and really reliable like most great stuff.
I always use dd before I sell an old computer with a drive and no OS installed. Silly as it sounds an old scsi drive that I once purchased at a used computer store actually had all of a dentists patient files on it unencrypted. Fortunately I am not the type that snoops, but the so called Windows IT guy that sold off the computer parts should have known better!