ZPOOL_CONFIG_FRU
if (nvlist_lookup_string(nv, ZPOOL_CONFIG_FRU, &fru) == 0 &&
(void) nvlist_lookup_string(vdev, ZPOOL_CONFIG_FRU, &oldfru);
if (nvlist_lookup_string(nv, ZPOOL_CONFIG_FRU, &vd->vdev_fru) == 0)
fnvlist_add_string(nv, ZPOOL_CONFIG_FRU, vd->vdev_fru);