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I have a 500Gb HDD hard disk in my Laptop, and I want to sell it, so I am asking if I can format it such that no one can recover my old data, and if yes, How can I do that? Thanks in advance

marked as duplicate by karel, Rinzwind, pomsky, Fabby, Eliah Kagan Jun 13 at 20:00

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  • if you choose "slow" format this resets all of the bits to 0. It's impossible to recover the data from there. – tatsu Jun 13 at 8:11
  • @tatsu Thank you sir, can i do it when i boot by usb? – user905942 Jun 13 at 8:12
  • yes you can install dd and gparted is already install on the liveUSB this answer will probably proove quite useful to you : askubuntu.com/a/359547/307184 – tatsu Jun 13 at 8:14

You can securely delete all the files with a program like shred
It overwrites the files before deleting them, so that a recovery wont get success

You can also overwrite all the HDD and, then, format it

See shred program : http://manpages.ubuntu.com/manpages/trusty/man1/shred.1.html
Or overwrite with dd if=/dev/urandom of=/dev/sdX bs=4096 status=progress then format the drive

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