Hey, Here is a patch to store the rw images in the cache directory. Regarding the volatile flag, things are a little more complex than what I thought initially. The "guix system" help menu states that: --8<---------------cut here---------------start------------->8--- --volatile for 'image', make the root file system volatile --8<---------------cut here---------------end--------------->8--- because for an image, it often makes sense to have the root file system persistent. For the 'vm' command however, it's probably the other way around as we would prefer not to copy the huge image files if possible. I feel like creating a '--volatile-image' and a '--persistent-vm' option is going to make things too much complex. WDYT? Thanks, Mathieu