I want to use Mojave and Ventura on my 2019 MacBook Pro. Which is better, for me, to format the drive with Mojave, and then add Ventura or to format the drive with Ventura and then add Mojave? My laptop can run both systems independently of each other.
MacBook Pro 15″
In your case I don't believe it would much matter. Both OSs will use the APFS drive format with GUID partition map.
The trick would be figuring out how to get the installer for the second OS. Recovery mode might work, but exactly which OS will be offered for reinstall is uncertain.
I would start with Mojave.
Once that is installed, create a bootable installer on a USB flash drive for that OS. You'll use this to reinstall Mojave after you upgrade this installation to Ventura.
Upgrade this Mojave OS to Ventura. That will upgrade the startup drive to APFS format and install the two startup volumes required for Ventura's operation; "Macintosh HD" and "Macintosh HD - Data".
Then, with that the Ventura OS in place, use Disk Utility to add another APFS volume, perhaps named "macOS Mojave" (?), onto which you will install that OS.
Finally, use the bootable Mojave installer to install that OS on the previously created third APFS volume.
In your case I don't believe it would much matter. Both OSs will use the APFS drive format with GUID partition map.
The trick would be figuring out how to get the installer for the second OS. Recovery mode might work, but exactly which OS will be offered for reinstall is uncertain.
I would start with Mojave.
Once that is installed, create a bootable installer on a USB flash drive for that OS. You'll use this to reinstall Mojave after you upgrade this installation to Ventura.
Upgrade this Mojave OS to Ventura. That will upgrade the startup drive to APFS format and install the two startup volumes required for Ventura's operation; "Macintosh HD" and "Macintosh HD - Data".
Then, with that the Ventura OS in place, use Disk Utility to add another APFS volume, perhaps named "macOS Mojave" (?), onto which you will install that OS.
Finally, use the bootable Mojave installer to install that OS on the previously created third APFS volume.
I did this simpler:
Apple has added several enhancements to APFS since Mojave and if the principal booted operating system will be Ventura, then use its APFS formatting for it, and then add the Mojave volume with its own APFS formatting.
And then, you need to configure each operating system to avoid Spotlight indexing each other, Time Machine backups, synched information, ignoring certain mounted volumes, and so forth. Not quite as simple as two volumes ignorant of one another.
Yes, VikingOSx, you're right: the order of install DOES make a difference (somewhere along the line), and your suggestion that indexing conflicts are the root of the problem makes sense. I am attempting the identical action as ElliotL, I am also on a 2019 MacBook Pro, and whether I install Mojave first or Ventura first, I get "disk incompatibility" alerts either way, and I have NO IDEA where or how to begin configuring each operating system!! 😳 😳
With the confession that I am rudderless, floundering, in water 'wa-a-ay over my head here, might there exist a benevolent soul out there with the time and altruistic nature to be interested in creating a clear-cut, point-by-point configuration checklist for successful Mojave~Ventura OS co-existence? I pledge eternal gratefulness in advance for such enlightenment, lieges-at-large.
I am attempting the identical action as ElliotL, I am also on a 2019 MacBook Pro, and whether I install Mojave first or Ventura first, I get "disk incompatibility"
Forget worrying about it, it's been that way here for years.
Could you please clarify how do you set up Spotlight and all? If I add Catalina as ignored volume under Mojave, then it gets added to ignored under Catalina too. E.g. Spotlight ignores are shared between different versions of macOS.
To use Mojave and Ventura, which should I use as my base system to format the drive first and then add the other one?
