I'm going to sell a computer hard drive on the Internet, it's a 500GB SATA hard drive, I really used it 3 or 2 years ago, I never used it again, I used about 20 or 40% of the space.
I have read about various tools and used Hardwipe, first I deleted the volume and recreated it, then with the program (option to clean free space) I used the GOST R 50739-95 method, when it finished then I did it again with the random method (both It took about 6 hours, in total I spent 2 days on this task, and I had several interruptions so I had to disconnect and continue the overwrite).
I have read an article on the internet (I shouldn't believe everything I read on the internet, but that's why I am asking this question), where it mentions that overwriting these random bytes is not enough and even if I used the DoD 5220.22-M method the data could To be recoverable, it mentions that a good method is degaussing (but this is really crazy, that is, a disk that used so little space), is this information really true? Should I use a Gutmann method?
Thanks