I do have a current HFS+ volume that is not encrypted, and I would like to encrypt it (which is the main goal). As part of this, I figured I may want to (or need to) convert this volume to an APFS volume.
First of all: is that possible at all (the volume is RAID5)?
Next: Is this path doable:
- shrink the HFS+ volume (less then half of the volume is used)
- create a new (encrypted) APFS volume on the open space
- copy data from HFS+ volume to the APFS volume
- erase HFS+ volume to allow for more space for the APFS to grow.
(sorry. I am no file system expert)
That won't work. We can only "shrink" or expand the last volume on the disk, we do not move partition start points.
Note: We do not support encryption on APFS volumes as there is still a kernel panic bug in macOS. You are welcome to encrypt using Disk Utility, it can erase a SoftRAID volume as encrypted, but you are likely to get occasional kernel panics.
Is it possible to use diskutil to convert an HFS+ volume to APFS? Will data be preserved during the conversion?
diskutil does not understand SoftRAID volumes, so no.
You can use SoftRAID to create a APFS volume, then use Disk Utility to erase it as encrypted if you want to test it out.
Thanks!

