This was done because there are now lots of resource.fs.zfs.statechange
events being posted but they do not include the state. For the moment
the state must always be healthy but there's no harm in making this
explicit.
Native ZFS for Linux! ZFS is an advanced file system and volume manager
which was originally developed for Solaris. It has been successfully
ported to FreeBSD and now there is a functional Linux ZFS kernel port
too. The port currently includes a fully functional and stable SPA, DMU,
and ZVOL with a ZFS Posix Layer (ZPL) on the way!