I used shred to erase my HDD but after leaving for a few hours and then returning, I found the screen was filled with "Error failed to write to entry ignoring read only file system". I restarted my machine, now it gives me the 1962 no OS found error, as I expected. Was the "failed to write to entry" suppose to happen? and did it securely wipe the files as I wanted? this is the first time I've used shred on a whole drive, so I'm not sure what to expect.
I used the command:
shred -vfz -n 10 /dev/sda
sudo
when you useshred
which is probably why you received the error. Also, you need to run Ubuntu from a live session DVD or USB or you won't be able to erase everything properly. – mchid Aug 10 '19 at 09:29