Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Rbfinch570

macrumors member
Original poster
Jul 22, 2017
49
31
I have an iMac 21.5, 2017, 1tb ssd drive. I've never had an issue installing an OSX until this install. Does anybody have an answer that doesn't require me to formatt my hd? I left an image.
 

Attachments

  • Screen Shot 2018-09-28 at 7.57.33 PM.png
    Screen Shot 2018-09-28 at 7.57.33 PM.png
    1 MB · Views: 197
I have an iMac 21.5, 2017, 1tb ssd drive. I've never had an issue installing an OSX until this install. Does anybody have an answer that doesn't require me to formatt my hd? I left an image.
Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.
You'll need to erase your drive and perform a clean install.
 
Your drive was formatted with a legacy MBR, a GUID partition type is a requirement to run macOS.
You'll need to erase your drive and perform a clean install.

Does High Sierra support booting from an MBR drive?
 
Crap. I have to completly whip my drive? Is there something special I have to do when I format the drive?
 
Crap. I have to completly whip my drive? Is there something special I have to do when I format the drive?
Try to back up first, do you have an external drive or a Time Capsule? If so you should back up to it with Time Machine.

Afterwards Boot by holding CMD+OPT+R after hitting the power button. This will boot you to the Mojave RecoveryOS. From there open Disk Utility. GO to the menu bar at the top and under "View" select "Show All Devices".

You will see a section on the left that says "Internal"; select the top-level drive, then click "Erase" button on the top-middle of disk utility. In the drop down name your drive: "Macintosh HD", select APFS, make sure the scheme is "GUID Partition Map". Click Erase.
Then Close Disk Utility.

After you close Disk Utility select the "Install macOS" option (should have the Mojave icon). Begin the installation (will take a while since it has to download the installer), and you are good to go.

After installation, during setup you can restore from time machine backup if you backed up.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.