Re: zero filling a storage device (was: dd and mbr)

From: Ralf Mardorf <ralf-mardorf_at_riseup.net>
Date: Fri, 14 Jan 2022 17:10:21 UTC
On Fri, 14 Jan 2022 18:00:39 +0100, Ralf Mardorf wrote:
>Hi,
>
>zero filling is fishy for several reasons. It's never secure!
>However, I won't comment zero filling. I'm not an expert and to lazy to
>search for links.
>
>Related to the addressable blocks and real physical locations I've got
>a link at hand.
>
>On Fri, 14 Jan 2022 15:55:58 +1100, Greg 'groggy' Lehey wrote:
>>proof of the contrary  
>
>Due to
>https://en.wikipedia.org/wiki/Wear_leveling
>the only way that could be (but not necessarily is) secure, is a secure
>erase command provided by the firmware.
>
>Regards,
>Ralf

PS: IIRC SSDs provide more disk space under the hood, than accessible by
a user. So you can't outwit wear leveling by overwriting the complete
disk. Probably it's still better to overwrite the complete accessible
disk space, than not to do so.