Disk Utility cannot unmount disk

"It is pretty easy that you just need to right click on the disk that "unable to unmount" >>>select reveal that file in finder >>> then reject the disk ( remember to quit DU) >>> then reopen DU again >>> and now you are done, you can remove the partition as usual

Cheers"

Thanks! Did the trick!

I had mounted using sshfs, and got the same error.

Tried to umount, but failed. Even when the process running was killed, it couldnt be umounted properly.

Tried with hdituil, it worked for me, without having to restart.

hdiutil eject -force <mounted drive>

SSHFS was used to mount the drive from the network by sshing.

Hope this helps someone...

To order to fix that i unpluged my hard drive and then replug it in then reboot and now i can!!😁

Thank you so much for this suggestion!!! It's the only thing that worked! My external Seagate drive is now formatted to Mac - and I can use it!