Create APFS RAM disk on macOS High Sierra

Question

usually creating RAM disks works with the following commands

hdid -nomount ram://

Returns e.g. /dev/disk2 Then I would format

Answer 1

Found a solution:

hdid -nomount ram://
diskutil erasedisk   

where is taken from diskutil listFilesystems from the "Personality" column. Yes, it seems weird to me too that you may have to quote this parameter, e.g. when specifying case-sensitive variants, but oh well...

is 2048 * desired size in megabytes

The last command formats the RAM disk and mounts it to /Volumes/

It seems to be the case that when now entering diskutil list that you will see two new disks, the one hdid created, and a synthesized one.

To destroy the RAM disk again, call diskutil eject

, e.g. diskutil eject /dev/disk2

This will do all the work for you, unmounting the /Volumes/ path and destroy the two disks, releasing your memory.

Keep in mind that the minimum/maximum values for depend on the chosen . Also, cannot always be chosen arbitrarily. Exemplary, FAT32 requires it to consist of upper-case letters!

Cheers!