The initramfs has a reduced set of modules to boot and then
in diskless mode hands over to the 'real' OS for all userspace
to use the more substantial root filesystem with all of the modules.
However one exception is kernel module autoload, which induces modprobe
to run in the initial mount namespace unconditionally.
Thus, preserve the ramfs drivers (just in case) but have the autoloading
pivot
to the normal root filesystem to get the full complement of modules.
Have imgutil complete the capture process, splitting work
between target and repository.
Provide hook through kcmdline to induce installtodisk.
Have installimage reboot system cleanly when done.
Have new /etc/confluent in cloned system.
Hook for post scripts to execute.
When going to zram, things were solid for space reduction as
data was written, however memory could no longer be reclaimed.
It turns out that zram supports TRIM, and by telling xfs discard,
we have it do trim-on-demand. It is by default off out of performance
concerns, but I don't think that applies to a zram backed filesystem.
