Can't eject external disk. In use by Finder.

[tobindia]

My MacBook Air is almost out of available disk, so I've exported all of my photos (30K+) to an external disk, thinking I could safely delete many of the photos from my MBA. When I try to eject the external disk, I get a message it can't be ejected because it's in use by Finder -- even after several hours. What's up?

 

[chscag]

That's because the Photos progams now has ties to your external hard drive with the photos on it. Reboot and then try to eject the external disk.

 

[tobindia]

I tried to reboot, but my MBA wouldn't come up at all! I finally unplugged the external drive. (I know, I know.) The MBA booted up and appears to be ok. What now?

 

[IWT]

The MBA booted up and appears to be ok. What now?

Well the MBA is fine; good. What about the EHD? I think that you need to remount it and establish that its contents are okay. You could reconnect to Photos, but that might cause the same problem as before - though it shouldn't really. Lots of folks keep their photos on an EHD to save space.

If you just open the EHD and make sure that the pictures are there - you could also run Disk Utility (DU) > First Aid on the EHD.

Final point - as of now you have no Backup of your Photos Library - all your pictures are on the EHD. That means you really need to BU the EHD.

One way of doing this is to use a cloning software like Carbon Copy Cloner (CCC) or SuperDuper! (SD!). You have to pay for these apps but, once purchased, you can use either one to create a clone BU of your MBA which would be a great BU asset and be bootable.

Ian

 

[badshoehabit]

Amateur here - would Force Quit have worked?

 

[ferrarr]

How is the drive formatted? Did you format/erase the drive, using Disk Utility, before exporting the images?

 

[tobindia]

In answer to TWT:

I reconnected the EHD. The photos all seem OK. I can copy them to another device. I can print them. Etc. But when i try to eject the EHD (after a few hour), I get the following message “The disk “ST D” couldn’t be ejected because the Finder is still using it. Stop the Finder action and then try to eject the disk again.” Of course, I don’t know what the Finder action is!

When I try to run Disk Utility First Aid on the EHD, I get “First Aid could not unmount the volume for repair.” I presume that that’s because Finder is using it in some way.

My HDD is backed up using Time Machine, so cloning shouldn’t be necessary, at least not yet.

In answer to ferrarr: The EHD is formatted as FAT32.

 

[ferrarr]

The next time you want to eject the drive and you get that popup window, press "option+command+esc" at the same time. You will get a Force Quit Applications popup window, select Finder, then click the relaunch button. See if the drive has been or can be ejected, now.

edit: Also, FAT32 is a cross platform file system, as it works with Windows OS, Mac OS, and most other OS's. It's not an ideal for long term Mac use, you may want to reformat the drive as Mac Extended Journaled (HFS+), only if you are using the drive with Macs exclusively. Be sure to have a backup or clone of the drive before proceeding.

 

[jpdemers]

Same problem with an M1 Mini, with an external drive formatted APFS and used for a spare Time Machine backup. (Belt-and-suspenders here: I like to keep a spare backup in a drawer, air-gapped from the rest of my setup.)
At first I thought it was Spotlight indexing the drive, but even giving it a day to complete, Disk Utility still reported the drive "in use by Finder." No clue why Finder is hanging on to it, but re-launching Finder solves the problem. Picking "Force quit" from the Apple menu and selecting Finder is the more obvious way to do this. (If option+command+esc is something you've committed to memory, you've got other problems!)