How clean is clean?

[bruffstar]

Hello,

This is my first post on the forum, its can probably be filed under 'absolute noob' but here goes...

I have a 1tb WD External HHD which I don't need any more and am looking to sell. My question is simple, how good is the data erase in the mac disk utility. If I sell it, I want it to be really clean.... 0% chance of data recovery. Not that I have much to hide, but my data is my data, would not want 'ibiza 08 with the lads' suddenly surfacing on the tinterwebs haha

The settings I used were.... Format: Mac OS Extended (Journaled) and Security: The first level of the security options, 'Zero Out Data'.

It formatted with no errors and the disk appears to be totally empty again.

Is this enough? If I run it through disk utility again and erase with the same settings, does this double the effectiveness or is that a waste of time? Was 'Mac OS Extended' the best format to use?

Thanks for any info!

Cheers,

Brian

[pcimage]

"Zero out data" should be plenty good enough, assuming that's what it actually did.

Did it take several hours to compete the erase?

[bruffstar]

"Zero out data" should be plenty good enough, assuming that's what it actually did.

Did it take several hours to compete the erase?

Yes.. it took 7 hours.

[pcimage]

Should be good enough

If you wanna be sure and for peace of mind, download a demo of some recovery software (e.g. RStudio) and run it through the drive. It should find absolutely nothing.

[bruffstar]

Thank you for the info pcimage!

[data-medics]

Yes, MacOS secure format is all you need.

[HaQue]

agree, but you will wonder anyways, so I recommend doing what pcimage said anyway.

FWIW I buy a LOT of flash memory on ebay. I always run DR software just to see...

[Izualim]

ohhh Haque after years working in datarecovery i realized that most of the times you don't want to know what's inside hahahaha.

[CleanestRoom]

It's generally considered impossible to recover data that has been zero'd once.

Some shredders/erasers offer 'multiple' passes, this is for extremely paranoid people, i don't think multiple passes is necessary at all but people can do as they wish.