[[ solved ]]
I have a stack of SATA hard drives that I need to erase.
I have a USB drive dock, a box that a drive can be set into that connects to my computer via USB-3.
I am using DD to write zeros to the raw device, in this case, /dev/sdf.
No matter the actual size of the drive dd stops at about 3 to 7 gb. These are 300 gb to 3 TB drives.
I am not mounting the drives, but I do ensure they are visible to the system with lsblk. To change drives I turn off the dock. The drive then disappears from lsblk. When I insert a different drive and turn the dock back on again /dev/sdf re-appears.
Are all my drives bad? If they are I will need to have them “professionally” destroyed at about $25 a drive.
Next Update –
I started with a USB to SATA adapter that looked like a small box with a SATA connector on one edge and a USB cable coming out of one side, it had a power supply that connected to the small box - everything out in the open.
Then I went to a drive toaster - a dock where you slot the drive into a hole in the top of the dock, again powered and USB-3 (blue connector)
As of this update I have opened my USB-3 external drive and removed it’s native drive and put in one of the 1TB drives I wish to erase. I also switched to my production laptop. Now I have issued a dd command and it has written so far 28GB from /dev/urandom.
I think this will finally work. - I am marking this solved.
Use the
shredcommand instead. See https://www.freecodecamp.org/news/securely-erasing-a-disk-and-file-using-linux-command-shred/ for options on how to use it, for drives it’s a bit further down.Depending on the sensitivity of the data on the drives I would always suggest a “professional” shredding service that destroys the physical disk as well.