There is no label for "Zero Out Data". Would that be the same as moving the slider all the way to the left in the Security Options dialog box when I've started the Erase function of Disk Utility?
Mac Pro, macOS 12.4
Writing zeros to a disk is a good way to make it difficult to restore files from a disk. You definitely want to do this if you give away your disk.
The option all the way on the left isn't the one you want. It redoes the file system and marks all data as unused, but you can likely recover some of that data. Security option 2 does want you want, plus some random data for good measure. It would be very difficult to recover after that. Higher security options exist if you are paranoid.
Anecdote: I bought a Memory Stick from Gamestop about 15 years ago. It had been formatted, so no files were visible when viewing it on my computer. However, I was able to use Photorec to restore several MP3s and JPEGs. They definitely had not zeroed out the drive, or Photorec wouldn't have found anything.
If you don't think that zeroing out a disk is important for removing data, try this: Load a drive with photos, format it with no security in Disk Utility, then run PhotoRec. You will likely find most of the photos. Try again after using Disk Utility security options 2-4 and you won't find anything at all.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
https://www.cgsecurity.org/wiki/PhotoRec
Writing zeros to a disk is a good way to make it difficult to restore files from a disk. You definitely want to do this if you give away your disk.
The option all the way on the left isn't the one you want. It redoes the file system and marks all data as unused, but you can likely recover some of that data. Security option 2 does want you want, plus some random data for good measure. It would be very difficult to recover after that. Higher security options exist if you are paranoid.
Anecdote: I bought a Memory Stick from Gamestop about 15 years ago. It had been formatted, so no files were visible when viewing it on my computer. However, I was able to use Photorec to restore several MP3s and JPEGs. They definitely had not zeroed out the drive, or Photorec wouldn't have found anything.
If you don't think that zeroing out a disk is important for removing data, try this: Load a drive with photos, format it with no security in Disk Utility, then run PhotoRec. You will likely find most of the photos. Try again after using Disk Utility security options 2-4 and you won't find anything at all.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support
https://www.cgsecurity.org/wiki/PhotoRec
If the external drive is SSD, NOT advisable (at least I would not for my SSD). SSD is not the same as HDD. HDD can be reconstructed from just reading sectors, and HDD can be written until it finally gives out and there is no buffering of data. SSD media uses a "header sector" to encode order among the blocks, but each block has a limited number of writes (albeit a very very large number of times), with those writes being "buffered". When you zero out an SSD you fill up that buffer almost instantly and it may clog ... "break hardware with software". The way the SSD encrypts the ordering and encrypts the data in each block all you need to do is "format at header" and every block-chain is instantly broken with almost no way to reconstruct what is on the drive.
To add to the very good advise from previous posting.
If the idea is to insure the dats on the SSD ? can not be retrieved there is not need to zero out the drive.
Even a Professional Data Recovery Company will tell the Client - the chances of recovery any meaningful data from a SSD Drive is extremely low and not with the expense to even attempt.
Even a Rotational Drive, recovery of enough meaningful Data will marginal at best. ( Marginal meaning some data will be recovered but not all )
I should have explained that the drive is an external drive by Seagate. It is older technology. I assume it is not SSD.
I’m following the instructions in this webpage: https://www.lifewire.com/use-disk-utility-to-create-a-raid-1-mirror-array-2260917. I don’t know why this article tells me to “zero out” the drives.
Zero-out of full SSDs may not even get all sectors. SSDs keep a percentage of the drive unused ... to lengthen the life of the drive by having some sectors not-written for periods. Then the unused sectors are swapped for used sectors so those can rest. Zero out, even if it does not clog the write-buffers may not over-write the unused blocks because the drive considers them not active until the control software rotates them back in.
Truly ... early SSDs could be killed by filling the write-buffers, and the ONLY hope was to connect to ONLY power (no data) and hope that it will EVENTUALLY clear the write-buffer.
Is it currently the best way to "zero" a SSD and HDD (before giving it away etc) just to encrypt and then decrypt it with FileVault?
p.s. Recently a big local newspaper's "data security" journalist caused a little fire in her basement while destroying a SSD (or maybe the whole laptop and its battery) with a hammer (to make 100% sure "reporter's privilege" was not violated). Then the the fire department arrived (and other officials noticed something was going on...) and the "data security" journalist was criticised and embarrassed for not knowing better how to do that properly.
To whom the the above reply intended for ?
Tend to disagree on the Zero Out the Internal Drive for the reasons presented earlier.
Plus, a great way to shorten the life of the drive.
SSD Drive do have a Lifespan before they too fail
How do I set security options to Zero Out Data when I erase an external drive with Disk Utility.
