Can I use the Nevada build 62 ZFS boot/root support with the new ZFS boot and installation features?
Systems that already have ZFS root file systems can be bfu’d to build 90, but bfu does not convert the legacy mounts (of /, /var, and so on) to ZFS mounts. Backwards bfu to releases that don’t support ZFS boot is prohibited. We recommend that you reinstall your systems at some future time to achieve the standard ZFS boot configuration provided in this release, which uses ZFS mounts, not legacy mounts. However, the system continues to boot with legacy mounts, at least for now.