External Hard Drive on Mac Won't Mount

Question

I can't mount an external hard drive. I have tried booting into Safe-Mode, mounting via Disk Utility and running First Aid, which won't proceed due to the following error:

diskutil eject disk1 Volume timed out while waiting to eject

I have also gone through the steps oulined here and here, as well as using Clean My Mac.

Any suggestions?

Answer 1

There is a 3rd party app named Mountain which I use on my mac. It puts an icon in your menu bar and when you click on it. it will show a list of Volumes and you can mount or unmount them. The app is $6 but has a free trial period so you can test it and see if it solves your problem. See image below.

Answer 2

I have encountered this problem but in my case, Bootcamp had created the problem. I mounted the disk in Windows (Bootcamp) and apparently, the disk did not eject properly. So when I switched to Mac OS, I found the disk unmounted but not able to eject it. In Disk Utility it appeared pale. So I did like below:

• Step 1

sudo lsof | grep "/Volumes"

You would see the result something like this:

mds       1071     root    6r      DIR    1,2       8192     2 /Volumes/BOOTCAMP
mds       1071     root   11r      DIR    1,2       8192     2 /Volumes/BOOTCAMP

• Step 2

The second column is the id of a process that makes the disk in use. So you should do this:

sudo kill [processId]

In my example:

sudo kill 1071

Then your disk is free to be ejected by this command:

diskutil eject [diskIdentifier]