When getting rid of any old computer it is always a good idea to make sure that the hard drive has been securely erased before getting rid of it.
My method for doing this involves booting up using an Ubuntu Desktop live disk/usb and using the shred command in Terminal.
Using Terminal enter the following commands:
sudo disk -l
- fdisk -l will list all the drives currently connected, make a note of the hard drive you wish to erase, in my case it was “/dev/sda”. Partitions will usually be marked as “/dev/sda1” and “/dev/sda2” etc.
sudo shred -v -n3 -z /dev/sda
- shred will erase the hard drive by writing random data to it.
- -v will enable verbose and display the progress of the shred command in the terminal window.
- -n3 will write random data to the entire hard drive three times.
- -z will run a final pass writing zeros to the entire hard drive.
- /dev/sda is the hard drive that is going to be erased.
An alternative to erasing the hard drive would be to physically destroy the hard drive platter to make the data unrecoverable.
Source:
https://askubuntu.com/questions/17640/how-can-i-securely-erase-a-hard-drive