Unable to install Clean version of Mojave on an external drive

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Unable to install Clean version of Mojave on an external drive

Hello, I am running Mojave on a Mac Pro Mid 2010 with a metal-capable card. I have downloaded the Mojave installer, and am trying to install a clean copy of Mojave on an external drive.

I run the installer program, I select the drive. (it's partitioned to Mac OS extended, GUID, though I've also tried APFS GUID.) It says it's running the installer, and after 4 minutes or so, asks to restart to do the installation. HOWEVER, it restarts to the current boot drive, and the external drive just has a folder entitled "macOS Install Data" No further installation is done, and the program has quit.

The software I'm using isn't re-written to 64 bit, yet, so Catalina is out of the question.

I've tried many variations on this theme without my drive eating to Mojave.

Any help is appreciated. Thank you

Posted on May 17, 2020 9:51 PM

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Answer 1

Best reply

Matti Haveri

Level 6

14,508 points

May 18, 2020 1:55 AM in response to Captain Marsupial

Mojave can run from Mac OS Extended but the Mojave updates don't run on it. Mojave installer should convert the disk to APFS but I think it is best to convert to or erase as APFS (GUID) before installing. Mac firmware may need updating for APFS support but the Mojave installer should do it.

Have you tried to re-download a fresh Mojave installer and make a flash installer and boot from that to install?

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Answer 2

May 19, 2020 8:35 AM in response to Matti Haveri

The metal capable card doesn’t show the screen during any of the pre-boot procedures. Apparently this is common for these cards. So no safe-boot, no option boot, and no recovery mode. Good thought, but I tried those. I hope these comments are useful for others in the same boat.

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Answer 3

May 18, 2020 6:51 PM in response to Matti Haveri

Ultimately I had to run the installer from a boot disk thumb drive. The installer wouldn't function through my regular drive. Thanks for the help.

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Answer 4

May 18, 2020 11:09 PM in response to Captain Marsupial

Glad you solved it. Maybe booting in safe mode could also have solved the problem?

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Unable to install Clean version of Mojave on an external drive

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