Adding HFS+ partition to APFS SSD drive

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Level 1

8 points

Adding HFS+ partition to APFS SSD drive

MacBook Pro 2017. I have OS Catalina installed on the SSD. Partitioned the SSD ing DIsc Utility, the second formatted as HFS+ capable of accepting High Sierra. SO far so good.

But now I want to install High Sierra, yet when I restart using OPTION, only the original drive shows up. How can I get High Sierra installed on the volume I just partitioned?

I followed Apple's set up instructions but they do not work unless you are upgrading to, say, VEntura.

MacBook Pro 15″, macOS 10.15

Posted on Dec 21, 2024 10:25 AM

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Answer 1

HWTech

Level 9

61,412 points

Dec 21, 2024 10:58 AM in response to lovely272

First, I would delete that partition. I don't recommend partitioning any drive because sooner or later people realize that one or more of the partitions is too small....and the only way to fix it is by starting completely over.

A better option is to create a new APFS volume and install macOS into the new APFS volume. A new APFS volume behaves very much like a partition, but without needing to resize anything which also makes it much safer. Or, install the other OS onto an external USB3 SSD.

Use more than one version of macOS on Mac - Apple Support

In order to install an older version of macOS onto another drive or partition, you first need to create a bootable macOS USB installer using the instructions in the following Apple article:

Create a bootable installer for macOS - Apple Support

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Answer 2

dialabrain

Level 10

126,755 points

Dec 21, 2024 10:58 AM in response to lovely272

You may need to create a High Sierra USB bootable installer, boot from that, then install High Sierra to the partition. It would be simpler to create a High Sierra virtual machine and get rid of the partition.

Personally I don't se any reason to be running High Sierra.

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