I need to run Mountain Lion on an external SSD drive for some older programs I use on my Mac Pro 5,1. Should I (can I?) use APFS format or HFS? If I format APFS can I go back to HFS by reformatting the drive? Thanks for any insights.
Mac Pro
Thanks! I'm repurposing two boot SSDs, a Mountain Lion HFS formatted and a High Sierra APFS formatted. Basically, I want to swap the contents of the drives so have cloned both onto HD bootable partitions. Can I reformat the APFS formatted SSD to HFS and clone the Mountain Lion partition on the HD to it? I would then repeat the process by reformatting the HFS formatted SSD to APFS and cloning the High Sierra HD partition onto it.
Mountain Lion cannot read APFS formatted file systems.
You cannot boot Mountain Lion stored on an APFS file system. Any data disks you have formatted APFS cannot be read by Mountain Lion.
If I am understanding what you want to do, that should work.
Is APFS good for Mountain Lion?
