I have several separate installs of Linux on my machine, and reboot to whichever one is appropriate. I'm wondering if it is possible to switch from one to the other without a full reboot by doing something like, say, copying over fstab with the partitions for the new install listed and then
Obviously, the kernel would not change, but that's OK, I'm hoping to just change the working partitions. I also take it as obvious that this would have to be done from the command line with nothing running (if that's even possible). Or is the idea null and void and sheer madness from the get-go?
The reason for this is that I normally experiment with radical changes (like moving to the 'amd64' kernel in Debian) in a separate 'experimental' install. Rebooting to start it up is of course just fine, but it would be cool if I could sorta jump over to that install without an entire reboot. You could think of this as just changing the root partition on the fly, but maybe that is not possible at all.
Yup, it's possible, as I learn below. If you don't need to swap out the kernel itself use 'chroot'. If you want to simulate a complete reboot use 'kexec'.