I decided to part with an old Mac mini that I had upgraded with a solid state drive (SSD). It wasn’t until I had erased the partition with Disk Utility that I realized I should have turned on FileVault encryption before attempting to erase it. This would have saved me hours of work trying to figure out how to securely erase an SSD. By encrypting the drive first, it would have been impossible to read any data off the drive after an erase.
There is no Secure Erase option in Disk Utility for an SSD (which I was hoping for):
With an SSD drive, Secure Erase and Erasing Free Space are not available in Disk Utility. These options are not needed for an SSD drive because a standard erase makes it difficult to recover data from an SSD. For more security, consider turning on FileVault encryption when you start using your SSD drive.
I didn’t feel totally comfortable without a true secure erase of the drive. After some searching, I came across an answer on Ask Different about ATA Security Erase, which is a command that can be issued to the drive to erase all its data.
In order to accomplish this, I purchased a copy of Parted Magic and downloaded the ISO file which could be used to create a bootable CD to load a copy of Linux to be able to run Parted Magic and then finally run its Erase Disk utility.
If you are thinking of securely erasing your Mac’s SSD, save yourself some time by enabling FileVault. If you hadn’t already done so, it will take hours to encrypt your drive, but it’s probably the the most secure way to set the data up for deletion (short of physically destroying the drive).
Some rabbit holes I went down to avoid:
- Apparently booting Linux off of a USB drive is not an easy thing to do on a Mac (it seems you have to set up an alternative boot manager). Just create a bootable CD, if you are able.
- Burning a disk image to a CD is no longer an option in Disk Utility. This must be done through the Finder instead.