Solaris 11 does not work without ZFS. It is the only supported root file system. Keep in mind that Solaris ZFS is largely incompatible with anything that exis

Solaris 11 does not work without ZFS. It is the only supported root file system. Keep in mind that Solaris ZFS is largely incompatible with anything that exists in an open source OS. ZFS started out by incrementing pool and dataset versions as features were added. The pool version that will be created by default in Solaris 11.4 cannot be used by ZFS in illumos, FreeBSD, or Linux. The open source versions of ZFS (found in illumos, FreeBSD, OpenZFS, ZFS on Linux, OpenZFS on Windows) use feature flags. By default, pools created with these will likely use a pool version that says "I have feature flags", which Solaris ZFS will no understand and will refuse to import. All implementations of ZFS should be able to create a pool with an explicitly old pool version and be able to be imported everywhere. That doesn't mean that pool will be useful for everything. For instance, open source ZFS does not have dataset aliasing, a feature I added in Solaris ZFS after the SoLongAndThanksForAllTheFish commit but before Solaris 11 was released. This feature is required for Solaris Zones.