Anyone dual booting Ventura/Monterey and pre-APFS OSes?

[retta283]

I've been stewing back and forth about whether to try adding a modern macOS to my 2012 iMac to gain easier access to newer apps, but I am unsure of how this procedure is going to work given my complicated setup. Dual-boot is even an understatement, I run 5 partitions of macOS on the machine, but the experience should (hopefully) be the same. I use primarily Sierra and Mavericks on it, and it is crucial that I retain access to these OSes. I am not willing to cede my legacy app catalog on this machine to get to a newer OS.

Obviously the main stumbling block seems to be that all of these partitions are not APFS. That and I'm not quite sure what the patcher does to the EFI boot screen, if it will even see these partitions anymore. Is it possible for me to clear one of my existing partitions for Monterey or Ventura and convert solely that partition to APFS, and retain easy access to Option-booting the older versions? Can the APFS partition see the older partitions? I know that the old Ones will not see the APFS, I can deal with that. Used to have that problem with Windows 98 not seeing 2000 or XP as it was NTFS, couldn't read it. Any details would be appreciated.

Edit: Perhaps seems strange to post this in the Early Intel section, but I figure that most people still using pre-HS/Mojave OSes are here anyway.

 

[theMarble]

For a while, I dual-booted Big Sur and Snow Leopard on a MacBook7,1. Installs went perfectly fine, you can do it in either order from memory.

You can share files from Big Sur to Snow Leopard, but not the other way around as Snow Leopard obviously doesn't support APFS.

 

[retta283]

For a while, I dual-booted Big Sur and Snow Leopard on a MacBook7,1. Installs went perfectly fine, you can do it in either order from memory.

You can share files from Big Sur to Snow Leopard, but not the other way around as Snow Leopard obviously doesn't support APFS.

This is what I had hoped for, thanks. macOS has always been pretty lenient with multiple OS installs, Windows back when required you to go in order from oldest to newest, otherwise it became a disaster that was very difficult to remedy. Just wasn't sure with how the APFS affects the boot loader, would hate to get locked out of the rest of the machine.

 

[weckart]

My iMac 2011 is triple booting Monterey, High Sierra and Mavericks. All show up under Monterey. Monterey won't show under Mavericks, of course. I have High Sierra and Monterey sharing one drive and Mavericks on an external TB drive. I have quite a few OSes on my Mac Pro running everything from Snow Leopard to Ventura and Win 10.

My setups are such that my computers will boot automatically to the OCLP boot picker and after a few seconds boot the last used volume. If I want to boot a legacy OS, I just hold down the option key to bypass OCLP altogether. Never had a problem with APFS's and HFS+'s coexisting.