Final tasks

This exercise should be performed at the end of the course only after explicit order from teacher!

General steps

Fill Bootcamp feedback form using link you received in you mailbox

Remove private data

Open terminal and execute commands:

sudo su
dd if=/dev/zero of=/dev/sda bs=8M count=1

This command will delete boot sector of the disk.

Optional approach to remove private data

Delete user folder

  1. Logoff out of graphical session
  2. Press Ctrl+Alt+F1 to activate text console
  3. Log in as student with his password
  4. Execute following commands in command line:

    sudo su
    cd /
    rm -rf /home/student
    mkdir /home/student
    chown student:student /home/student
    exit
    exit
  1. Press Ctrl+Alt+F7 (or ..F8, ..F9 etc.) to switch to graphical console
  2. Log in as student and check that default look is successfully restored

Fill empty space with zeroes

After files are deleted from file system entries, actual file content remains in disk. Therefore file content can be (at least, partially) recovered. To avoid this, you can write zeroes in all free space. Note that depending on disk speed and free space it can take x hours to execute, therefore you can leave computer doing work and switch it off when it is done with a command as a root user:

dd if=/dev/zero of=zero.file bs=1024 status=progress; rm zero.file; shutdown -P now

Created by Valdis Vītoliņš on 2017-01-03 08:07
Last modified by Valdis Vītoliņš on 2020-02-21 14:46
 
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