This is split from #120. At least some of `/var` needs to be preserved, `/run` needs to be discarded. Very likely other paths. References: - https://manpages.debian.org/testing/manpages/hier.7.en.html - https://manpages.debian.org/testing/systemd/file-hierarchy.7.en.html - https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html - https://www.debian.org/doc/debian-policy/ch-opersys.html#file-system-hierarchy - https://docs.fedoraproject.org/en-US/packaging-guidelines/#_filesystem_layout