https://jeltsch.org/en/tags/erasing/Recent content in Erasing on Michael’s DomainHugoen-usCopyright © 2002 - 2026 Michael Jeltsch.Fri, 24 Jul 2026 00:18:18 +0300https://jeltsch.org/en/how_to_erase_hard_drives_shred_dd/Sun, 25 Jan 2009 00:00:00 +0000https://jeltsch.org/en/how_to_erase_hard_drives_shred_dd/<p>You could write zeros to the whole hard drive<code>dd if=/dev/zero of=/dev/hda</code>For newer versions of dd, you can monitor the progress:<code>dd if=/dev/zero of=/dev/hda status=progress</code>However, it has been recommended to write a few passes of random noise (n = 3 is the default). If the writing process entirely got rid of the magnetic history and your source of randomness was perfect, a single pass would ALWAYS be enough. In reality, you only need n&gt;1 if you are dealing with the state secrets since recovering anything after an n=1 erase requires special equipment which you cannot buy in any store. <code>shred -vfz -n3 /dev/hda</code></p>