Boot Mac Pro from MBP HDD

[elliots11]

I have a 2009 Mac Pro running El Capitan. I tried creating an install USB thumb drive disk for El Cap so that I could set up a new/spare boot HDD for experimentation using the Terminal boot disk creation method, but it kept hanging and wouldn't install.

I also have a 2012 MBP, also on El Cap, and have connected the HDD that I want to run the Mac Pro to it via USB adapter. So now I'm using internet recovery to set up the HDD to run OSX and once it's done I plan to pop it back in the Mac Pro and start it up.

Now I've heard people tell me that it doesn't matter what computer you use to create a boot drive, it'll have all the drivers on there for every Mac. Is that true? And if not, is there a way to get those drivers?

 

[dianeoforegon]

There is a firmware update as part of the install of High Sierra. Your old 2009 Mac Pro doesn't meet requirements. I'm doubtful that you would be able to run High Sierra even if you successfully install on an external from your old Mac.

There are probably a hack you can use.

 

[elliots11]

These were both on El Capitan, either way the internet recovery didn't recognize drive I was using, probably due to the adapters, so I couldn't install. But thanks for the help and that's good to know for later.