2011 MacBook Pro data erasure

Does this laptop use a hard drive or an SSD?

Was Filevault enabled on the drive before you erased it?

These are important details since hard drives and SSDs work differently and require different procedures to make sure the data has been destroyed or over written.

If the laptop uses an SSD, then the data has been destroyed due to how SSDs work. So if the laptop has an SSD, then you are done.

If the laptop uses a hard drive, then the data is only destroyed if Filevault was fully enabled at the time you erased the drive.

If Filevault was not enabled on the hard drive when you erased it, then the data is still hidden on the drive since Disk Utility by default only performs a simple erase by creating a new partition table which still leaves all the data hidden on the hard drive. For an unencrypted hard drive, you must erase the drive by writing a single pass of zeroes to the whole hard drive so that any data hidden on the hard drive is overwritten with zeroes. Unfortunately I don't think the macOS Disk Utility GUI interface allows for a "secure erase" option anymore because it would cause unnecessary wear to an SSD. It is possible to use the command line to write zeroes to the hard drive either using "dd" or possibly even using the "secure erase" option of the command line utility "diskutil" (command line part of the Disk Utility app). You will need to boot into Internet Recovery Mode using Command + Option + R in order to access the Terminal app to use these command line utilities. ShredOS is a free open source option which will make a bootable USB stick which can be used to write zeroes to the hard drive. You will want to download the 64bit version of the .img file and use it as a source for Etcher (Mac/Windows/Linux) which will "burn" the image file to a USB stick and make the USB stick bootable. Option Boot the ShredOS USB stick and select the orange icon most likely labeled "EFI".

annapotamus wrote:

The computer has a hard drive and it isn't mine so I don't know if Filevault was enabled but the owner is sufficiently untech-y that they don't know what that is; so I suspect it wasn't enabled.

I would assume that as well since most people don't seem to enable it.

I will try to follow your instructions when I get a bit of time;

The ShredOS option is probably the easiest to do. I've never tried it yet, since I only recently discovered the project which is using software that has been around for a while, but just not bundled this way.

if I can't make that work I will destroy the machine rather than pass it on to anyone else.

Don't destroy the laptop. It is very easy to remove the hard drive so you can just destroy the hard drive and have the laptop itself recycled or refurbished.

On macOS Yosemite, the last supported operating system for the MacBook Pro 2011, you can choose the security of the erase. If you chose a lower level, a data recovery app like EaseUS will likely be able to get the files back. If you chose a higher level, it will be unlikely that you will be able to get the files back.

If you use a Mac, then you may be interested in the MacTracker app which has all sorts of information regarding every Apple device and OS released. I find it very useful when needing to know more about a specific device or OS when using my Mac.

If you want to know which versions of macOS are compatible with various Apple hardware, then here is an excellent article (especially if you are not using a Mac at the time):

https://eshop.macsales.com/guides/Mac_OS_X_Compatibility

macdillondinwiddie wrote:

On macOS Yosemite, the last supported operating system for the MacBook Pro 2011,

FYI, a 2011 laptop can run up to macOS 10.13 High Sierra.

I was fixing a MacBook pro 2011 that had Yosemite, which threw me off.