I wanted to use a ramdisk. SoI created one, filled it with 3GB data and unmounted it. Like this:

diskutil erasevolume HFS+ 'ramdisk' `hdiutil attach -nomount ram://8388608`
cp -pr some3GBdirectory /Volumes/ramdisk
umount /Volumes/ramdisk

That last statement removed /Volumes/ramdisk from the directory tree, but the 3GB stays allocated by a process called diskimages-helper. I need to kill it with SIGKILL to get the process removed and my memory back. What is the nice way to remove the ramdisk and get my memory completely freed?

1 Answer 1


The first command tells you which disk it is, e.g. /dev/disk2

Then diskutil eject /dev/disk2 will eject the disk and free the memory

  • 1
    The eject verb can take a volume name, e.g. diskutil eject ramdisk in your example, which still unmounts the entire disk without needing to do the lookup of the disk identifier yourself.
    – grg
    Jan 3, 2019 at 0:15

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .