“Disk Not Ejected Properly” on a Mac: why it happens

How do I eject a drive on a Mac?

Use any of these, then wait until the drive disappears from the Finder sidebar before you unplug it:

1. In the Finder sidebar, click the Eject button next to the drive’s name.
2. Or select the drive, then choose File > Eject, or press Command-E.
3. Or, on the desktop, drag the drive’s icon to the Trash.

Shutting down works too. For a Time Machine backup disk, Apple’s advice is to eject the disk or shut down your Mac before you disconnect it.

Why won’t my Mac let me eject the drive?

If you can’t eject a drive, an app or another user is probably still using a file on it. Apple’s steps, in order:

1. Quit the apps using files on the drive, or close the documents that are on it, then eject again. Press Command-Tab to see which apps are open.
2. If it still won’t eject, choose Apple menu > Log Out, log in again, and eject the drive.
3. As a last step, choose Apple menu > Shut Down. Disconnect the drive, then start up your Mac again.

Why does the alert appear when I didn’t unplug anything?

Then the drive dropped off by itself, and the connection is the place to look. These are Apple’s checks for drives and USB devices:

• Connect it directly. Plug the drive straight into your Mac, without a hub or extension cable.
• Check the cable, then swap it. Make sure it’s firmly connected at both ends, then try a different cable and a different port.
• Give it power. If the drive has a power adapter, use it. A drive without its own power cable shouldn’t be plugged into another device without one: connect it to your Mac, or to a device that has its own power cable.
• Match the hub. If you do use a hub, the drive and the hub should be the same speed.
• Unplug the rest. Disconnect other USB devices and see whether the drive stays connected, then add them back one at a time.

Notice when it happens: during a large copy, after your Mac wakes from sleep, or only when something else is plugged in. That tells you whether to look at the cable, the power or the hub first.

Did I lose any data?

Check, to be sure. Apple’s pages say to eject a drive, or shut down your Mac, before you disconnect it. Open the files you were copying or saving when the drive disconnected, and copy them again if any won’t open. Then check the drive itself with First Aid:

1. Open Disk Utility. It’s in Applications > Utilities, or search for it with Spotlight.
2. Choose View > Show All Devices.
3. Select the drive’s volume, click First Aid, then click Run. Repeat for each container on the drive, then for the drive itself.

If First Aid says the disk appears to be OK or has been repaired, you’re done. Apple also notes that a damaged file system can make macOS mount a drive read-only, with an error such as “The operation can’t be completed because the disk is read-only”. First Aid is the first fix for that too. If First Aid says the disk is about to fail, copy your files off and replace the drive.

Questions people also ask

What’s the shortcut to eject a drive on a Mac?

Select the drive in the Finder and press Command-E.

Is it OK to shut down instead of ejecting?

Yes. Apple’s advice for a backup disk is to eject it or shut down your Mac before you disconnect it.

Why does my external drive keep disconnecting?

The drive keeps losing its connection. Try another cable and port, plug it straight into your Mac without a hub, and use its power adapter if it has one.

Why doesn’t my drive show up after I plug it back in?

It may not have mounted. External drive not showing up on a Mac? walks through Finder’s settings, Disk Utility’s Mount button and First Aid.