How do we replace an existing/operating root file system associated with device_A with a root file system on another device?
E.g., If Linux was booted with a ram disk as the root file system, then after boot how could we switch to use a root file on a hard disk?
Clearly we can't unmount the root file system from ram disk, then mount it from the hard disk because we can't unmount the root file system.
But surely there is a way to remount/overlay an existing root file system associated with one device, with another root file system from another device?
--Christine
