How to delete personal stuff from laptop permanently!

Question

I am selling my laptop with ubuntu OS. How can I make sure that I have deleted all my stuff from the laptop so the new use cannot access any of my stuff. I want to keep ubuntu OS though. Also I am asking I'm not very good with technology and any help will be appreciated!

The best way is going to be format and reinstall the OS – nullmeta Apr 19 '17 at 01:17 — nullmeta, Apr 19 '17 at 01:17

b_laoshi · Answer 1 · 2017-04-19T01:29:11.220

Don't just format or reinstall! Old data that hasn't been overwritten can still be recovered! Someone came to me with a computer once that had had many users. The current user had accidentally deleted ALL of her important files and wanted to know if I could get them back. You wouldn't believe the stuff I was able to dig up from multiple previous installs from the users before her!

First, use DBAN (download, burn it, boot from it) to digitally shred the entire contents of the drive (used and free space). This will take some time, but it will make file recovery virtually impossible on an HDD
After you have shredded the contents of the drive, then reinstall Ubuntu.

Bleachbit is available for Ubuntu in the (16.04) repos, but I would advise against this approach. If you forget to securely erase an existing file or "free space", you may leave something behind that could be discovered. The same goes for the shred command. You're better off overwriting the entire disk with random data using a tool like DBAN.

For the record I was going to mention killdisk :) – nullmeta Apr 19 '17 at 01:24 — nullmeta, Apr 19 '17 at 01:24

score 3 · Answer 2 · answered Apr 19 '17 at 06:45

It depends on your disk. If you have a classical one (with plates) then the DBAN way provided in @b_laoshi answer is correct. Wipe and reinstall.

If you have an SSD then you do not need to do the wipe (and should not). The way free space is managed by SSDs is different from classical HDDs - the blocks marked for deletion are not available and are actually cleaned by a garbage collector process. Wiping the disk does not help and actually lowers the lifetime of the disk.

In such a case just make a complete reinstall of the OS, choosing to destroy existing data.

Note: the erased data which is on an SSD may still be available via a complicated forensics analysis but the only realistic solution in that case is to destroy the disk.

How to delete personal stuff from laptop permanently!

2 Answers2