Wiping a Mac's SSD

Continuing the discussion from Safari 16.6:

I think you may be confusing two topics.

To wipe an SSD so that old data is inaccessible by software, you can do what you used to do on hard drives. Boot into recovery mode. Delete the macOS APFS container. Between TRIM and the T2 chip’s encryption, that should be enough to delete every “thread of anything old left on it”. Then (still in recovery mode), you can reinstall macOS, which will create a new APFS container to hold everything.

When people talk about this kind of deletion not being sufficient, they are talking about erasing the flash chips such that data recovery experts can’t manually examine the flash chips (or install data-recovery SSD firmware) and reconstruct the deleted data.

The TRIM and encryption used by Apple on nearly all Macs with internal SSDs will be sufficient to make sure that nothing erased can be read by software, which is all you need to make sure your new macOS installation doesn’t get corrupted by files from the prior installation.

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David C., Hi! I was trying to keep my original comment kind of simple without too much geek-speak.

I cannot tell you how many times I weren’t into recovery mode, deleted the APFS container, and reinstalled the Mac OS. This is what the geniuses at Apple told me to do more than once.

What I needed was option 2 that you described, which Apple cannot do locally. Cupertino can, and did. I paid for Fedex both ways with their word that what they were to do would absolutely be successful.

It was.

Normally, if I could have booted from an external drive, I would have booted from the external drive, erase the internal SSD, then reformat as a Master Boot Record ( Windows.) Then shutdown, exercise some patience, start back up on the external disk, reformat of APFS encrypted and be on my merry way. That has always been my sure way that any and all remnants are no longer around. I did not do this often in the past but enough that I could remember how to do it without referring to my notes. Did it more on wifey’s MB Air. I have no clue how she comes to mess her machine up so bad… But she does, and she has me to fix it…………. Thanks for the conversation………

That’s very strange. Deleted and TRIMed data is literally no longer acessible to software. That can’t be the problem.

I suppose it is possible that there was corruption in one of the other APFS containers that hold the boot-loader. That can be wiped, but you need another Mac and the Configurator utility to re-create that data afterward, because deleting them will otherwise leave you with a bricked device.

I’m glad to hear that Apple did something that worked, but I’d really love to know what they actually did.

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