spa_get_stats
error = spa_get_stats(poolname, &cfg, NULL, 0);
VERIFY(spa_get_stats(spa_name(spa), &config, NULL, 0) == 0);
extern int spa_get_stats(const char *pool, nvlist_t **config, char *altroot,
error = spa_get_stats(zc->zc_name, &config, zc->zc_value,