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[Solved] Downgrade from Mojave to High Sierra

Joined
Oct 26, 2017
Messages
3
To downgrade to High Sierra without erasing your drive is quite easy as long as you are using APFS.

1. If you have converted your drive to APFS, simply create a new volume in the same container as your boot drive. Do not set any size restrictions on that new volume.
2. Install High Sierra on that new volume according to this thread.
3. Boot it up and copy the files you need from the old volume to the new volume. The nice thing with the APFS file system is that the volumes dynamically share the same free space within the container. When finished simply delete the old drive.

I just did that and managed to downgrade to High Sierra without erasing anything. You of course need some free space on your old drive so that you have some space to work with.
 
Joined
Apr 23, 2012
Messages
47
Motherboard
Gigabyte Z97X-UD3H-BK
CPU
i7
Graphics
GTX 960
Can I just run the HS installer from Mojave with the new container as the target?

**EDIT: Nope. Mojave gets weirded out by it being older.

To downgrade to High Sierra without erasing your drive is quite easy as long as you are using APFS.

1. If you have converted your drive to APFS, simply create a new volume in the same container as your boot drive. Do not set any size restrictions on that new volume.
2. Install High Sierra on that new volume according to this thread.
3. Boot it up and copy the files you need from the old volume to the new volume. The nice thing with the APFS file system is that the volumes dynamically share the same free space within the container. When finished simply delete the old drive.

I just did that and managed to downgrade to High Sierra without erasing anything. You of course need some free space on your old drive so that you have some space to work with.
 
Joined
Oct 26, 2017
Messages
3
Can I just run the HS installer from Mojave with the new container as the target?

**EDIT: Nope. Mojave gets weirded out by it being older.
The new volume should be the target, in the same container as your old boot volume.
In APFS you have volumes inside containers. You only need one container on your disk. But you should create a new volume inside the container, beside your old volume. In the new volume you install HS.
Dont mix the two things up, containers and volumes.
The advantage of working with volumes is that they dynamically share the free space of the container. And they show up like ”harddrives” on your desktop. No need any longer for the old partitioning nightmare.
Hope it works out for you!
 
Last edited:
Joined
Oct 6, 2019
Messages
15
Motherboard
Asus FX505GM
CPU
i7-8750H/HM370
Graphics
UHD 630 & GTX 1060
Mobile Phone
Android
I've formatted my hard drive several times now, but the same message keeps appearing in my installer. Any other possible solutions?
Thanks!
 
Joined
Mar 14, 2019
Messages
4
Motherboard
MSI GL62
CPU
i7-6700HQ
Graphics
GTX 960M
Mac
MacBook Pro
Mobile Phone
Android, iOS
error when trying boot on HS installer Error loading kernel cache (0xe), how?
 
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