If I had multiple external drives then we’d see them listed under disk3, disk4, etc. Since I only have 1 external drive connected to the computer, it only shows the one external disk as disk2. What we’re looking for is our external drive. The synthesized one, disk1, is how the Apple File System has organized itself into various volumes and partitions for things like booting, recovery mode, data storage, etc. Disk0 is, of course, the drive built into this Mac. In this arrangement we have 3 disks that the Mac sees marked as internal, synthesized, and external / physical to help us see. There’s a lot here, but don’t get too intimidated. Hit enter on your keyboard, and the Terminal will now list out all the drives connected to your machine. This invokes the Disk Utility function (the same one the app uses) and has it list out the disks, hence the list command. Once the Terminal is open, type in the following command diskutil list To do that, open your Terminal folder either from Spotlight or by going to the Applications Folder, then the Utilities folder, then double-clicking on Terminal. We need to know the path the Mac uses to connect to it. Finding the Diskįor the purposes of my demonstrating this, my external drive will be called “Test”. We’re only going to be focused on erasing the drive in this video other things like multiple partitions or volumes, encryption, etc.

This guide is crafted for those who are newer to the Terminal or just want a little more guidance with it. I’m going to take this step-by-step and walk you through what each command does so you can understand it. Lastly, I’m going to show you how to do a more secure erase if you need to do that. I’m going to show you how to locate the disk you want to erase, unmount that disk, and then erase that disk in a particular format.

And, if nothing else, it’s a good tool to keep in your back pocket. While the Terminal may not be the first thing you think about using when manipulating disk, it can give you more options and control over your disks.

Erasing disk failed mac