How to do Low Level Format (Hard Format) for a Laptop HardDrive

Question

I have 2 questions

1. Can we know weather a Hard Drive has done Low Level format or not. Somehow using a tool ?
2. How to do Low Level Format (Hard Format) for a Laptop HardDrive

Answer 1

You can't really do a 'proper' oldschool low level format with modern drives - they require specialised software, and it only really needs to be done once, at the place its made.

You can however wipe the drive with dban - with modern drives a single pass is often enough, DOD recommends 7 passes, and the guttmann method basically runs every possible wiping algorithm for pretty much every sort of drive ever made.

Depends on how much time you're willing to spend.

more info here if you are into the science of it.

Answer 2

With Low-Level you mean to overwrite the drive with zeros or random data?

For Question 2: You can do this with every Linux Live CD and the dd command. Something like

$ dd if=/dev/zero of=/dev/sdX

should do the trick. Alternatively you can use a specialised distribution like DBAN.

Answer 3

You can check content of the hard drive with hexdump. Actual destroying data with dd mentioned above or with shred.

Answer 4

If you want data security, buy an industrial shredder. All sorts of interesting forensic techniques can be applied to hard drives of all types to retrieve data you "thought" was gone.