The `clone` command allows you to clone a configuration from a system image to another one, or from the running config to another system image. The syntax is the reverse of the copy command.
To clone the running config to a system image:
vyos@vyos-rtr:~$ clone system config <system-image> from running
To clone from system image A to system image B:
vyos@vyos-rtr:~$ clone system config <system-image-B> from <system-image-A>