Do external USB drives need to be APFS?

[honeycombz]

Hey, recently upgraded to Mojave from High Sierra HFS, made my internals APFS but my externals which I use primarily for backup or emergency boot drives which are typically created via SuperDuper are still HFS. Does this matter? Do they need to be converted to APFS? Can I still smart update from APFS to external HFS? Is there a non-destructive method to convert HFS external USB to APFS? Thanks!

 

[casperes1996]

HFS+ is perfectly fine. If they are hard drives and not solid state I would even recommend keeping them HFS+.

As for non-destructively going to APFS that should still be possible with Disk Utility, yes, but keep in mind reversing is not possible without wiping the drive

 

[Fishrrman]

Platter based hard drives will be better left in HFS+.

Actually, you can leave a bootable Mojave backup drive in HFS+, too.

The only problem with leaving a Mojave boot drive in HFS+ is... you can't run "Software Update" on it. Found this out myself.
At least with Mojave, to run Software Update requires a drive formatted to APFS.

 

[honeycombz]

Guess I’ll just leave it HFS for now. No reason I can’t convert it down the road.

 

[Macsonic]

Using an external HD formatted as HFS+ in Mojave and so far working fine.

 

[Head_Unit]

OMG I made an external bootable which apparently during Big Sur install got re-reformatted APFS. Now, well https://forums.macrumors.com/thread...r-and-writing-to-external-apfs-drive.2292160/