could not unmount disk mac external hard drive

Could not unmount disk mac external hard drive how to#

There’s a bunch that you can do, but here’s the 5 formats you’ll most likely need. The next part of the command is the format of the drive, so we need to know how we’re going to use the drive. Not surprisingly, this is the same Force Eject command if you’ve ever used it in the GUI. The new command now reads (again with # being replaced with 2 in my case): diskutil unmountDisk /force /dev/disk# If the drive couldn’t be ejected, then hit the up arrow on your keyboard to bring up the previous message, then use the left and right arrows to navigate your cursor to just after the unmountDisk command and type in /force.

Hit enter, and after a second or two the Terminal should say that the drive was unmounted successfully. Remember to change the number behind disk to whatever number you had listed in your previous list command. Type in the following code, but change the # to the number of the disk you found in the previous section. You can, of course, do this through the GUI either by dragging the drive to the trash can or via right clicking, but since we’re already in the terminal I’m going to show you the command. Now we need to unmount the disk so we can ensure no other processes are working on it. Since we’re wiping the entire disk, we just need to know that this is disk2 and won’t worry about the other identifiers. The identifier shows you the disk and sector that the Mac uses for communicating with the drive. I can see section 2 is formatted as an ExFAT drive and is named Test, as well as its size, and the “Identifier”. The first, #0, is the partitioning system for the whole drive, #1 is the EFI for managing it, and #2 is the actual partition for the drive that I use. Depending on how many drives you have connected to your machine, both inside and out, your drive might have a different number, so just make sure to change that number accordingly. 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.

Could not unmount disk mac external hard drive how to#

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.