Just bought a mid-2014 MBP from ebay and I tried to update to Catalina but it said I need APFS to do that. I tried disk utility but the option is greyed out. I NEED a way to do it non-destructively. I have no way to backup my stuff as of right now.
Current OS – Mojave
Trying to update to – Catalina
Tried – Disk-Utility -> Edit -> Convert to APFS (Greyed out), lots of googling. Tried using diskutil apfs convert command but gave the error -69546
Best Answer
You should be able to convert to APFS from HFS+ non-destructively through macOS Recovery - if your Mac has the required recovery partition. The usual method to boot to recovery is to hold down ⌘-R immediately after a power-up or reboot. Disk Utility will then become available through the Recovery mode GUI.
This site claims that the conversion will be non-destructive when done through Recovery mode. It covers High Sierra as the latest macOS because APFS was introduced with High Sierra and this was germane to users back then. I cannot find anything to contradict this assertion.
Your milage may vary.