Installing High Sierra on an old HD problems...

[aaron321]

I have Mojave, but I'm trying to install High Sierra on an older HD because I need to see if anything is capable of running older software on my more modern Mac 5.1.

However, when I attempt to install High Sierra, it provides no options during installation, and appears to simply want to write over Mojave on my main drive with a simple restart.

How can I direct my Mac to actually install High Sierra on a specific hard drive that isn't my new one with Mojave?

I would've loved to just start up the old HD and install High Sierra from there, but my newer Mac Pro no longer boots the old HD, which had Tiger installed on it.

 

[tsialex]

I have Mojave, but I'm trying to install High Sierra on an older HD because I need to see if anything is capable of running older software on my more modern Mac 5.1.

However, when I attempt to install High Sierra, it provides no options during installation, and appears to simply want to write over Mojave on my main drive with a simple restart.

How can I direct my Mac to actually install High Sierra on a specific hard drive that isn't my new one with Mojave?

I would've loved to just start up the old HD and install High Sierra from there, but my newer Mac Pro no longer boots the old HD, which had Tiger installed on it.

The simplest and fail-safe way to do what you want:

1. make a createinstallmedia USB installer of 10.13.6
2. fully erase the HDD you want to install
3. remove all your other disks
4. boot from the createinstallmedia, format your HDD, do the install

 

[aaron321]

The simplest and fail-safe way to do what you want:

1. make a createinstallmedia USB installer of 10.13.6
2. fully erase the HDD you want to install
3. remove all your other disks
4. boot from the createinstallmedia, format your HDD, do the install

Thank you.