I was wondering, is it possible to upgrade the kernel using 'pacman -Syu' and then load the new kernel without rebooting the machine? Also, along the same lines (sort of), is it possible to edit the rc.conf file and then re-load the file without a reboot?
Kexec (included in archck kernel). Is would probably be a pain in the ass with the initrd though, and you can't do it while in X.
rc.conf provides data to various initscripts, so it would depend what changes you make. For example, networking changes can be applied by doing
I suppose you could change to init 1 and then back to 3/5, but even then, I don't think that would do everything - if you removed modules from the MODULES array for example, I don't think they would be unloaded that way.