Hello,
Maybe it's time to step back and ask a more basic question. What is it that you are trying to accomplish? I know that you are trying to do a pivot_root. But *why* are you trying to do a pivot_root? Why do you think you need to do it? What is the real-world problem that you are trying to solve?
I want to go back into an initramfs setting so that only the running kernel and one specific process remains. Goal is to be able to boot a new system from there with a new hard drive (for example mounted via nfs or some other way) withouth the need to reboot the entire kernel. The whole thing is running within a xen domU atm. So the new hard disk could be passed through via xend or mounted via nfs. And for cleanly terminating the first system I need to unmount the root filesystem and somehow replace the old init process with my specific process running in that initramfs setting. According to the pivot_root manpage, it should be possible to clear all dependencies to the old root fs so that it can be unmounted after the pivot_root command. And that's what not working for me.
K. Haselhorst