How do I boot from ubuntu on my USB drive so I can wipe the ubuntu file system on the hard drive? I have ubuntu on an exterior hard drive and want to boot from that so I can wipe the internal hard drive on a Dell system before I give it away.



You can boot from your USB stick and do dd on it, but be carefull not to wipe other drives.

Usually the command I do is simple:

sudo dd if=/dev/zero of=/dev/sdx bs=16M

NOTE: sdX should be the drive you're wiping. I only have an internal HD so the name is "sda", but for external drives could be sdb, sdc etc.

For my 1TB drive it takes about 3 and a half hours to wipe it with zeros.


It would probably be easiest to burn the Ubuntu image on the external drive to a disc and boot as a Live CD. Otherwise, if booting from the external hard drive is a requirement, follow many of the tutorials online concerning USB booting Linux.


If I understood clearly, you have an external HDD with an Ubuntu installed on it. You want to boot your system from that external hard drive, and use Ubuntu to wipe the internal HDD.

  1. Start your system, and go to the BIOS and change the boot priority in the following order:
    It won't be exactly like this but make sure the first boot device is USB so that your system boots from your external HDD. Then save and restart.

  2. When you are in Ubuntu, use Gparted to delete the data you have on your internal hard drive. You would probably have to unmount the partitions from your internal HDD before making any changes. Be careful about the data and the partitions you are trying to change. Make sure you have chosen the right partitions.

  • Actually, if he want to wipe his drive gparted won't do the job, requiring dd to wipe all data. – Amanda Jun 13 '13 at 21:10

To wipe the drive clean, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo dd if=/dev/zero of=/dev/sdx bs=4k conv=notrunc

If you would like to make multiple passes on your hard disk I would recommend using the shred command.

sudo shred -n2 -v /dev/sdx

Note: Replace x with your device ID.

  • In fact random is not needed for just wiping, regular users will never be able to recover a zeroed drive, not to mention it will take forever and a bit more depending to his drive size. DBAN for example takes almost 8 hours to do a simple zero pass on my 1TB drive. With dd and bs=16M I get the same result as if bs=32M, about 3 and a half hour. Random is only needed if you want to get out of the FEDs radar or something with the government. – Amanda Jun 13 '13 at 21:20
  • @Amanda I have modified that, after realizing it. – Mitch Jun 13 '13 at 21:21
  • No problem Mitch :D – Amanda Jun 13 '13 at 21:22

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