Fix various callbacks when using IPv6 based deployment.
Do not attempt to restore erroneously cloned zram partitions.
Convert LVM names to new LVM names consistent with source naming scheme.
Push new kernel command line into /boot/loader and /etc/kernel/cmdline.
With significant firstboot output, there was a tendency
for tail to be killed before it relayed all the content.
Change to run the firstboot in a subshell in the background,
and have tail explicitly run until that subshell naturally
exits and then tail will cleanly exit