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msim20 Author

Level 1

49 points

High Sierra install fails - "unable to unmount volume for repair"

Have a 2012 Mac Mini.

Running Sierra.

Third party SSD running Sierra for more than a year.

Sierra was installed over the previous version of OS.

When trying to install High Sierra, system takes me to a screen that says "unable to unmount volume for repair". Asks me to restart and back to normal login.

Checked the primary HDD via Disk Utility. Everything appears to be ok.

Searched the discussion forum and internet. No solution found.

Any ideas?

Thank you.

Posted on Sep 26, 2017 10:58 AM

126 replies

luic2

Level 1

8 points

Feb 2, 2018 8:28 AM in response to dianeoforegon

Been tryin this solution but I'm always having the message command not found or so. I'm on macOS Installer Utilities Terminal btw, coz Im basically stuck out in the installation. Thanks You.

Feb 2, 2018 7:44 PM in response to MBarrowclift

great explanation!!!! I appreciate the time it took you to type all that out. I took it to the geek squad today. Now I wish I had it here so I could try it.

Feb 5, 2018 11:46 AM in response to andy260

In Recovery mode -> Terminal, i entered the first command and i am getting sudo: command not found

cmaus

Level 1

20 points

Feb 5, 2018 11:47 AM in response to jaikishan30

You don’t do that from Recovery Mode.

Do it while your macOS is normally started.

Feb 7, 2018 9:23 AM in response to MBarrowclift

All good upto step 5, executing the command at step 6 gives error : “no such file or directory”

Feb 8, 2018 1:01 AM in response to dianeoforegon

Thanks for the update.. i really do not want to lose my data so any help on cloning would be really helpful..

High Sierra install fails - "unable to unmount volume for repair"