Great to hear that I can put everything one one drive.
In your case, if you want to install different versions of macOS, you will need to make sure that each partition is formatted with the appropriate file system for that version of macOS. For example, if you want to install macOS 10.6 Snow Leopard, you will need to format the partition with Mac OS Extended (Journaled). If you want to install macOS 10.15 Catalina or later, you will need to format the partition with the new Apple File System (APFS).
Good point! I've always used MacOS Extended journaled, but noticed that while doing a clean install of MacOS 10.14 (Mojave) on my Macbook Pro it formatted the (SSD) drive to APFS.
I can't say I've seen an option for APFS in
Disk Utility, so is it safe to assume that when doing a clean install of any MacOS/OSX version it formats the partition appropriately itself? If that's the case, is all all I need to do (prior to installing each OS) is split up the drive into the into the number of sections I need for my alternative OSes (using
Disk Utility)?
It's also important to note that some older versions of macOS may not be compatible with newer hardware, so you may need to check the system requirements for each version of macOS you want to install to ensure compatibility with your Mac Pro.
Thanks for mentioning this.
From other discussion threads I've learnt that the latest MacOS versions need to be patched in order to "fool" the Mac Pro into thinking it can use an otherwise incompatible OS. I'm a little skeptical, but having heard from others with good experiences I'd like to give it a go, and with a separate drive it's more or less risk-free.
Finally, it's a good idea to back up any important data on your Mac Pro before partitioning the drive or installing any new operating systems, as there is always a risk of data loss during these processes.
Yes! Many people (including myself) learn to backup
after having lost irreplaceable files, so now I have an internal Time Machine backup drive which does its thing all through the day, and an external USB-3 dual drive bay for an additional backup to a separate removable hard drive (I use Chronosync for this, and try to do it regularly).
Another excellent tip I got from another thread (concerning the installation of Windows on a separate drive) is to shut down the Mac Pro, then physically remove all drives except the ones you actually need for installing the new OS (in my case that would just leave the single drive where I wanted to have Windows on, and the Windows installer DVD).
OK, all the above seems pretty straightforward (once a little planning has been done concerning the amount of and size of each partition, the actual file system for each OS, and compatibility with the specific computer), but once that's all done I'll have the ability to boot into whatever OS I've installed, which is fine if I want to work in an "isolated environment" (i.e. apart from my usual files and folders), just in the same way as when I boot into Windows where I need to transfer files i'm working with on to a USB-flash drive, then reboot back into MacOS (or another MacOS version in the above case).
So how about integrating those "environments"?
Let's say my day to day OS is 10.13 (High Sierra) which I'm using now, but I want to reboot into 10.6 (Snow Leopard) for running some old Power-PC software, or 10.9 (Mavericks) for running some 32-bit apps which no longer work in High Sierra... would it be possible to access my home folder (belonging to 10.13) from either of those other OSes, or even logging into that home folder for a seamless experience? Or would the latter cause a mess with preferences etc. since I might be using different versions of the same apps?
