Portioning a MAC

Joined
Jul 11, 2015
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I have a MBP-13 2020 with 1GB drive I supply for work as BYOB device. It has some enterprise profiles installed making USB not work with hard drives and other software embedded into it.

I would like to reduce the 1GB partition and create a 256GB partition on another boot as my personal MAC and make it dual boot. Is this challenging task and require me to rebuild the work machine? Or simply reduce partition and install the other OS (would be MAC Catalina).
 
Joined
Apr 25, 2017
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macOS allows partition re-sizing on-the-fly. You can leave your work portion untouched and install a 2nd instance of macOS for personal use.

Use Disk Utility. You'll get a pie chart of your current partition and you can just drag it to the size you want or there's a text input field you can type into. Once that's all done, reboot and hold down the OPTION key to get the boot manager where you can boot from the new partition (or use it to set-up / install the OS on).
 
Joined
May 6, 2005
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I'm pretty sure they'll just show up like any other partition, where you can install MacOS and boot using option. I've only used this for bootable external drives, but if I didn't hold option while powering up or restarting, it would always go to the default drive. I think there might also be a way to pick a default to boot.

I would make sure to have it all backed up in case it gets borked.

And as long as you have internet that doesn't require a setup screen, you should be able to get into MacOS Recovery over the internet. A password is fine, but not if you're doing something like hotel internet where it connects you to a setup screen first where you have to enter some credentials or even just click to agree to terms and conditions.


It's apparently a bit different with Apple silicon.

 
Joined
Nov 23, 2015
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APFS gets weird and tricky about trying to dual boot off the same disk...

If it's work supplied and you can't plug in an external HDD, I'm wondering if that's at the OS or at the EFI level. If it's at the EFI level, you likely can't do it. If it's at the OS level, personally I'd opt for dual boot via an external HDD. Good ones are fast these days, especially over TB3.

Also, depending on just exactly which 2020 MBP it is, it may not be physically capable of running 10.15(Catalina)
 
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