ZPOOL_CONFIG_METASLAB_ARRAY
VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY,
fnvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY,