macOS 'The disk can't be ejected because it's in use' fix

30-Second Fix: Force Quit the Obvious Suspect

Before you dig into Terminal, try the dumb stuff. It works more often than you'd think.

1. Click the Apple menu → Force Quit (or hit Command+Option+Esc).
2. Look for any app that's actively using that disk. Typical culprits: Finder, Photos, Spotlight (mds), Time Machine (backupd).
3. Select the app and click Force Quit.
4. Try ejecting the disk again.

Still stuck? Don't waste time restarting Finder or relaunching the Dock. Move to the next fix.

5-Minute Fix: Find the Hidden Process with Terminal

The real fix is finding exactly which process is holding the disk open. Nine times out of ten, it's a background daemon or a third-party tool you forgot was running.

Open Terminal (Applications/Utilities). Run this command, replacing /Volumes/ExternalDrive with your disk's mount path:

lsof | grep '/Volumes/ExternalDrive' | grep -v 'com.apple'

That pipes the output through two filters: first it shows everything referencing your disk, then it removes Apple's own processes (because killing system daemons is a bad idea). You'll get something like:

Dropbox  1234  user  txt  REG  1,5  123456  789 /Volumes/ExternalDrive/somefile.txt

The first column is the process name, the second is the PID. Note that PID.

Now kill it — but gently first:

kill 1234

If the process ignores that, go nuclear:

kill -9 1234

Try ejecting the disk again. If it pops up again, keep reading.

15+ Minute Fix: Nuke Spotlight's Index or Rebuild

Spotlight's mds process loves to hold drives hostage. If you killed it and it comes back, or if lsof shows mds or mds_stores, you need to tell Spotlight to leave the drive alone.

Open System Settings (or System Preferences on older macOS) → Siri & Spotlight → Spotlight Privacy. Click the + button, find your external disk in the list, and add it. That tells Spotlight to ignore the drive entirely.

Wait 30 seconds, then try ejecting again. This works 99% of the time.

If you still can't eject, there's one more dirty trick: force unmount via Terminal. This can cause data loss if files are open, so only do it if you're sure nothing critical is writing.

diskutil unmount force /Volumes/ExternalDrive

That bypasses the stuck process entirely. The disk disappears from Finder immediately. Replug it and it'll mount cleanly.

If none of that works, you're looking at a corrupted disk. Run Disk Utility's First Aid on it. That's a different problem entirely, but it's worth checking after a force unmount.

Pro tip: If this keeps happening with a specific drive, check the drive's format. ExFAT drives are notorious for this on macOS Ventura. Convert to APFS or HFS+ if you can.