Update Caiman installer to allow installation into an existing root pool and dataset hierarchy
The Caiman installer, at least as I see in its gui-install form, is a binary which includes everything and allows little deviation from the one predefined installation scenario: request a partition, create the rpool, make the standard datasets, install the OS image from the Live Media and customize it (networking, user account data, timezones, changes to non-Live SMF profiles).
This tracked issue represents a desire to enable deviations from the one installation path: allow installing into existing rpools (yes, this works when done manually - including very old ZFS versions as the rpool, but is a major hassle to do repeatably), and to allow installation into the provided mountpoint which contains the rootfs hierarchy prepared by the user (i.e. as in http://wiki.openindiana.org/oi/Advanced+-+Split-root+installation instructions).
A custom rpool, instead of the one automatically created by the installer, might include features desired by a particular user - for example, enforcement of "copies=2" right from the pool's creation command to improve reliability of a system which can only house one HDD (i.e. a laptop), or enable the use of LZ4 compression for all of the rpool.
It could also permit coexistance of a new illumos distro (like OpenIndiana) with some older installation on the same pool for the purposes of upgrade and migration, if for some reason a direct upgrade is not feasible (I did such upgrades from SXCE into OI; some list members had problems with "pkg" so bad that they'd rather reinstall but not instantly lose their old OSes - so this is not a theoretical construct, but a feature with moderate demand).
In theory, allowing to install and customize the OI image "over" a prepared mounted dataset hierarchy (i.e. a clone of the old installation) could be a viable step in an upgrade as well, and not only in the split-root installations described above. But I wouldn't dare state that upgrades are so simple that this would solve the quest. They are not, and this is only a substantial simplification of the upgrade ;)