MAC OS COULD NOT UNMOUNT DISK MAC OS X
MAC OS COULD NOT UNMOUNT DISK INSTALL
MAC OS COULD NOT UNMOUNT DISK ARCHIVE
MAC OS COULD NOT UNMOUNT DISK PLUS
MAC OS COULD NOT UNMOUNT DISK SERIES

Or the deletion of important system files. WARNING: Improper use of the sudo command could lead to data loss IronMan:~ nbalkota$ sudo gpt recover /dev/disk1 If the last command was successful, disconnect and reconnect your disk, which should now be OKģ: Apple_Boot Recovery HD 650.0 MB disk0s3.Start terminal and use the 3 commands in bold red below (make sure to change the disk number to match your setup based on the first command).

MAC OS COULD NOT UNMOUNT DISK MAC OS X

I would guess the disk did not like being unplugged without using the eject command…Īnyway, salvation can come at no cost by using the Terminal in Mac OS X (assuming you have administrative rights): Don’t ask me how it got corrupted in the first place. In Disk Utility the drive device was listed, but no volume could be mounted due to a corrupted partition map. Now, I take pride in having never ever lost any data on my Macs since 1998, so I was concerned this might be the end of my record… The disk you inserted you inserted was not readable by this computer. Perfectly normal behaviour again.Today, as I intended to perform my regular Time Machine backup, I got welcomed by a very scary message when I connected my external hard disk to my MacBook. Only when a file was indeed open by a user process, unmounting was prevented. Normal mounting, unmounting, read/write operations. From then forth the Volume worked fine again. It may still fail, as the background processes, which failed, could be still in a irrecoverable state. This eventually worked after Finder's delete attempts have failed. Through the Terminal with sudo rm -R /path/to/troublesome/FileOrFolder.This creates a little more force, but likely it will still fail.

MAC OS COULD NOT UNMOUNT DISK PLUS

With Finder plus holding down ALT while emptying the Trash.

Likely this will fail, as it's a 'troubled file/folder'. I simply used Finder's native 'Compress' function from it's context menu.

MAC OS COULD NOT UNMOUNT DISK ARCHIVE

In my case it was a Classic Mac OS file with a resource fork that remained open, likely as some background disk parsing process (Spotlight, QuickLook, or thelike) hung on it.īackup that troubling data into a file archive (which preserves (Classic) Mac specific resource data). In detail:ĭetermine which file is accessed (with lsof orįseventer). Removing the troubled content can fix this permanently. My fix: Summarized: The ejection issue can be caused by corrupted or legacy file content on that Volume. My experience: I had a Volume which constantly could not be ejected properly (as in the OP's screenshots), and always needed a 'force eject', sometimes even a forceful physical disconnection (nor recommended! could damage your filesystem(s) on that disk) or a system shutdown to bypass that brute method. It runs with super user permissions ( sudo), so it sees all read/write access of all mounted file systems, and presents them in a very clear overview. There is a GUI alternative to the CLI app lsof:įseventer is a great file system access monitoring utility for various purposes.

MAC OS COULD NOT UNMOUNT DISK INSTALL

With brew cask install fseventer it may still be available on elder macOS versions. NOTE: fseventer works until OS X 10.10 Yosemite and the developer's page meanwhile got offline. ( Hat tip to Alec Jacobson's post for extra details.) It'll take longer, but it should pick up anything that's causing the disk to be un-ejectable. That will do a top down scan of the disk.

If that happens, try adding the +D argument (i.e. It can also hang, but you should give it at least a few minutes before you decide that's what happened.Īlso, sometimes the base command sudo lsof /Volumes/myDrive won't find anything. One final note, lsof can take a minute or two.

You should be able to eject the disk once the process/application has been killed.

MAC OS COULD NOT UNMOUNT DISK SERIES

Here's a series of escalating aggressiveness (using the example PID of 2158): kill 2158 Note that sometimes that doesn't work and a more aggressive form of kill must be used. From the above example, it would be: kill 2158 To do that, use the PID from the second column as the ID to kill. If you can't close the application manually, you can use the kill command to terminate it from the command line. For example, QuickLook doesn't show up as an application you can get to in the Dock. Closing the application directly is the best way to fix the issue. In this case, it's the QuickLook application that has a file open. Mds 89 root 23r DIR 52,3 432 2 /Volumes/Photosįinder 681 alans 14r DIR 52,3 432 2 /Volumes/Photos Mds 89 root 19r DIR 52,3 432 2 /Volumes/Photos The output will look something like this: COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME It can take a couple minutes to run, but once it's complete, it gives you a list of open files on the disk. The fastest and easiest way would be this :- sudo lsof /Volumes/myDrive

Mac os could not unmount disk