We want to configure Solaris for readonly boot using a ZFS snapshot for
the boot image. While this is similar to other uses, we want to make
those system files that must be writeable have no persistence beyond
reboot; only user data and perhaps /var would retain modifications past
a boot. Those system files that need to be writeable would be
instantiated by creation of a root clone at boottime.
Persistant reconfiguration would require the creation of a new boot image:
a) clone the current boot image to create an updateable image,
b) make modifications to the update clone,
c) take a snapshot of the update clone, and
d) designate that snapshot as the replacement bootfs.
However, using current mechanisms, updates of SMF-controlled
configuration would require a reboot during step b) using the update
clone, so that svccfg and svcadm operations could update the SMF
repository. In order to make this boot unnecessary, a natural solution
would seem to be to use the functionality currently restricted to the
buildtime executables svccfg-native and config-native, perhaps through
a svccfg -R option. Is this a reasonable approach or would this rope
be too easily tangled into a noose?
-JZ
