Formatting Hard drives

Author
Discussion

gotoPzero

Original Poster:

19,028 posts

204 months

Tuesday 3rd June
quotequote all
My last topic was deleted.

So, let me phrase it differently.

Will windows disk format (properties, format, full format) remove all data from a hard drive so if someone else was to use the hard drive would it then be really blank or is the old data there?

FiF

46,748 posts

266 months

Tuesday 3rd June
quotequote all
This is generally what I have done.

https://www.malwarebytes.com/cybersecurity/compute...

As it says it's more complicated with SSD.

You can use other software to overwrite the drive multiple times.

dundarach

5,670 posts

243 months

Tuesday 3rd June
quotequote all
The most important question is why?

If you're selling, take out and sell without, drives are cheap.

If you're skipping, take out and drill if you're really worried.

If you're repurposing, don't worry, just format.

Drives are as cheap as chips if you're more worried than a windows format, destroy the drive.

Or as posted, download\buy something else, or pendirve linux and format it??


otherman

2,241 posts

180 months

Tuesday 3rd June
quotequote all
gotoPzero said:
My last topic was deleted.

Will windows disk format (properties, format, full format) remove all data from a hard drive so if someone else was to use the hard drive would it then be really blank or is the old data there?
To answer your question no, format will only clear the File Allocation Table, all the data is still there and can be recovered.

gotoPzero

Original Poster:

19,028 posts

204 months

Tuesday 3rd June
quotequote all
Right, CBA then.

Will just drill and bin. Cheers all.


skyebear

890 posts

21 months

Tuesday 3rd June
quotequote all
Security researchers/the nosey often buy old drives/computers secondhand to see what data they can recover. Results are eye-widening on occasions.

Always worth ensuring any devices purchased come with (or add) DMR - Defective Media Retention. Means you can keep any drives that are replaced under warranty.

JoshSm

961 posts

52 months

Tuesday 3rd June
quotequote all
otherman said:
gotoPzero said:
My last topic was deleted.

Will windows disk format (properties, format, full format) remove all data from a hard drive so if someone else was to use the hard drive would it then be really blank or is the old data there?
To answer your question no, format will only clear the File Allocation Table, all the data is still there and can be recovered.
Pretty sure it's only quick format that does an allocation delete, full in theory does a resurfacing to zero which is why it takes so long by comparison.




TonyRPH

13,307 posts

183 months

Tuesday 3rd June
quotequote all
Boot from a Linux USB stick ( System Rescue is a good free option)

Then use dd to erase the disk.

dd if=/dev/zero of=/dev/sdX to overwrite it with zeros (or use if=/dev/urandom if you prefer)

"/dev/sdX" is the drive designation in Linux - /dev/sda is the first, /dev/sdb the second and so on.

The command fdisk -l will list the installed disks (for safety, only connect the disk(s) you wish to erase).

To erase the first disk in the system: dd if=/dev/urandom of=/dev/sda bs=1M status=progress

This will overwrite the entire disk with zeroes (/dev/zero) or random data (/dev/urandom).

Be aware that a large disk will take a while (usually a couple of hours) to erase. Do not interrupt the process, ensure it's allowed to complete.




Mr Pointy

12,521 posts

174 months

Tuesday 3rd June
quotequote all
Use Eraser - very easy to use:

https://eraser.heidi.ie/

JoshSm

961 posts

52 months

Tuesday 3rd June
quotequote all
FiF said:
This is generally what I have done.

https://www.malwarebytes.com/cybersecurity/compute...

As it says it's more complicated with SSD.

You can use other software to overwrite the drive multiple times.
Multiple overwrites aren't really necessary on anything modern HDD wise, we're well past the stage where is was possible to get anything back off the surface from residuals like it may have been in the past. Run a randomised write over the thing and the data is gone.

SSDs are only complicated because they don't waste life on overwrites/zeroing by default and spread the wear around, so you have to either really force it to fully erase or (if you cared enough to set it up) reset the encryption key.

Destruction is the option if you don't want to waste the time/expense on secure formatting and want something 100% guaranteed & certified not to have data slip out via a cockup.

Drive retention is usually a cheap option and worth the effort. Funny thing is how often people forget about the drives in their printers, copiers & other kit like that.

Ultimate paranoia is shredding anything with any possibility of storage, like the GPUs because they have updatable firmware. Seen that done before.

carguy45

628 posts

179 months

Tuesday 3rd June
quotequote all
Can only echo above. The question of intended usage of the disc and what is stored on it is an important one.

Quick format : less than a minute, but data is easily retrievable by anyone with even rudimentary computer skills and the right app.
Full format: takes longer but will make it much more difficult (though not impossible by any means) to retrieve the disk data.

You could go with multiple full formats (using different file systems) which, like adding layers of paint over grafitti, make it exponentially harder to find what's underneath. Particularly if you start using the disc after the last format so that you're also overwriting the old data. However it never truly makes it impossible to retrieve the original data, just difficult.

If the disc has any confidential/sensitive data that you absolutely 100% do not want anyone else seeing and is going to be in someone else's care, I would just destroy it and use a replacement disc. We deal with some sensitive data in work and all our drives have to be shredded when a computer is retired - even ones from printers/copiers and other devices.