Disk Utility cannot unmount disk
I am trying to reinstall snow lepord on a macbook pro. When I go to repartition the drive it fails and tells me that it cannot unmount the disk. Any ideas?
MacBook Pro, Mac OS X (10.6.7)
I am trying to reinstall snow lepord on a macbook pro. When I go to repartition the drive it fails and tells me that it cannot unmount the disk. Any ideas?
MacBook Pro, Mac OS X (10.6.7)
Since this is still the top hit for the question...
I know this is a major necropost, but just in case someone stumbles across this thread, here is the solution. I wish I had found the answer *before* I threw away those couple of "dead" drives, lol.
Some damaged disks do not show up with Disk Utility and DiskWarrior, and may hang and crash such repair utilities. Yet, there is a trick to repair such broken disks using Disk Arbitrator.
1. Open Disk Arbitrator and select "Activated - Block mounts." This prevents the damaged disk from crashing the repair utilities and allows such disks to be displayed by these utilities.
2. Connect the damaged disk.
3. Open Disk Utility or DiskWarrior. The damaged disk should show now and it should not crash the repair utility.
4. Deactivate Disk Arbitrator (uncheck the Activated box). This allows the repair utility to handle the damaged disk properly (mounting it once repaired).
5. Run Disk Utility or DiskWarrior.
Then, the utility should repair the disk, or at least, mount a Preview disk (DiskWarrior), allowing you to inspect and even copy or backup some files or the full disk, reformat it and restore it.
Here is where to get it:
Hi hoosier,
The primary cause of facing disk utility could not unmount hard drive is the modification of the boot drive or it is being used by some other process or application.
If the internal Mac hard drive is causing this problem due to macOS, recovery exists as partition and unable to change or unmount the Mac HD, then you should choose the network based drive or any powerful external hard drive.
Then boot from the Snow Leopard installer DVD. After the installer loads select your language and click on the Continue button. Do not install. Wait for the menubar to appear then select Disk Utility from the Utilities menu.
Try repartitioning again.
This is what I was already doing.
Sorry. You did not mention that. Is this drive already partitioned into more than one volume? If so, do you have any "links" between volumes? Have you tried first shutting down the computer, then restarting to the installer DVD? Is the drive partitioned using GUID?
It is currently only one volume, yes I have restarted but will try again now, and yes right now it is a GUID Partition Table.
Another restartd didn't work either.
No, don't just restart. Shutdown first - power off. Wait one minute before powering up.
Also, try repairing the drive if you haven't already tried.
I tried shutting down and waiting before powering back on that still didn't work, and when I hit repair disk it gives me "error: could not unmount disk".
Well, something is definitely awry with the drive. Do you have a bootable backup? If so, then I would boot from the backup, erase the internal drive, then restore from the backup.
I do not have a bootable backup just the files dragged onto an external hard drive. Are there any other ways to erace the internal one?
reset PRAM, then boot from DVD and try to repartition it
do you have other mac at hand? If so - you can use target mode to repair your drive
Not without losing everything. Well, then, let's try something different.
Boot into Single-user Mode:
After startup is completed you will be in command line mode and should see a prompt with a cursor positioned after it. At the prompt enter the following then press RETURN:
/sbin/fsck -fy
If you receive a message that says "***** FILE SYSTEM WAS MODIFIED *****" then re-run the command until you receive a message that says "** The volume (name_of_volume) appears to be OK." If you re-run the command more than seven times and do not get the OK message, then the drive cannot be repaired this way. If you were successful then enter:
reboot
and press RETURN to restart the computer.
you forgot mount / -uw before fsck )
Data loss is not an issue because I have all the files that I need backed up to an external hard drive.
I do have another mac wich is what I am posting from now because the one with the problem won't boot to anything but the disc.
Disk Utility cannot unmount disk