Index: stand/libsa/zfs/zfsimpl.c
===================================================================
--- stand/libsa/zfs/zfsimpl.c
+++ stand/libsa/zfs/zfsimpl.c
@@ -78,6 +78,7 @@
 static char *zfs_temp_buf, *zfs_temp_end, *zfs_temp_ptr;
 
 #define TEMP_SIZE	(1024 * 1024)
+#define ALL_LABELS_INVALID ((int)0xFFFFFFFF)
 
 static int zio_read(const spa_t *spa, const blkptr_t *bp, void *buf);
 static int zfs_get_root(const spa_t *spa, uint64_t *objid);
@@ -513,6 +514,20 @@
 	return (vdev);
 }
 
+static void
+vdev_delete_by_guid(uint64_t guid)
+{
+	vdev_t *dev, *kid;
+
+	if(dev = vdev_find(guid)) {
+		STAILQ_FOREACH(kid, &dev->v_children, v_childlink)
+			vdev_delete_by_guid(kid->v_guid);
+
+		STAILQ_REMOVE(&zfs_vdevs, dev, vdev, v_alllink);
+		free(dev);
+	}
+}
+
 static int
 vdev_init_from_nvlist(const unsigned char *nvlist, vdev_t *pvdev,
     vdev_t **vdevp, int is_newer)
@@ -766,6 +781,17 @@
 	return (spa);
 }
 
+static void
+spa_delete_by_guid(uint64_t guid)
+{
+	spa_t *spa;
+
+	if (spa = spa_find_by_guid(guid)) {
+		STAILQ_REMOVE(&zfs_pools, spa, spa, spa_link);
+		free(spa);
+	}
+}
+
 static const char *
 state_name(vdev_state_t state)
 {
@@ -929,7 +955,7 @@
 }
 
 static int
-vdev_probe(vdev_phys_read_t *_read, void *read_priv, spa_t **spap)
+vdev_probe_try(vdev_phys_read_t *_read, void *read_priv, spa_t **spap, int *tried_labels)
 {
 	vdev_t vtmp;
 	vdev_phys_t *vdev_label = (vdev_phys_t *) zap_scratch;
@@ -950,6 +976,7 @@
 	int i, l, rc, is_newer;
 	char *upbuf;
 	const struct uberblock *up;
+	int best_label = 0;
 
 	/*
 	 * Load the vdev label and figure out which
@@ -962,8 +989,10 @@
 	    (uint64_t)sizeof (vdev_label_t));
 
 	/* Test for minimum pool size. */
-	if (psize < SPA_MINDEVSIZE)
+	if (psize < SPA_MINDEVSIZE) {
+		*tried_labels = ALL_LABELS_INVALID;
 		return (EIO);
+	}
 
 	tmp_label = zfs_alloc(sizeof(vdev_phys_t));
 
@@ -990,16 +1019,21 @@
 		    DATA_TYPE_UINT64, NULL, &pool_txg) != 0)
 			continue;
 
-		if (best_txg <= pool_txg) {
+		if (best_txg <= pool_txg && (*tried_labels & (1 << l)) == 0) {
+			printf("ZFS: found label %d was written in newer txg\n", l);
 			best_txg = pool_txg;
+			best_label = l;
 			memcpy(vdev_label, tmp_label, sizeof (vdev_phys_t));
 		}
 	}
+	*tried_labels |= 1 << best_label;
 
 	zfs_free(tmp_label, sizeof (vdev_phys_t));
 
-	if (best_txg == 0)
+	if (best_txg == 0) {
+		*tried_labels = ALL_LABELS_INVALID;
 		return (EIO);
+	}
 
 	if (vdev_label->vp_nvlist[0] != NV_ENCODE_XDR)
 		return (EIO);
@@ -1077,20 +1111,25 @@
 	 */
 	if (nvlist_find(nvlist, ZPOOL_CONFIG_GUID, DATA_TYPE_UINT64,
 	    NULL, &guid) != 0) {
-		return (EIO);
+		rc = EIO;
+		goto err_delete_spa;
 	}
+
 	vdev = vdev_find(guid);
-	if (vdev && vdev->v_phys_read)	/* Has this vdev already been inited? */
-		return (EIO);
+	if (vdev && vdev->v_phys_read) { /* Has this vdev already been inited? */
+		rc = EIO;
+		goto err_delete_spa;
+	}
 
 	if (nvlist_find(nvlist, ZPOOL_CONFIG_VDEV_TREE, DATA_TYPE_NVLIST,
 	    NULL, &vdevs)) {
-		return (EIO);
+		rc = EIO;
+		goto err_delete_spa;
 	}
 
 	rc = vdev_init_from_nvlist(vdevs, NULL, &top_vdev, is_newer);
 	if (rc != 0)
-		return (rc);
+		goto err_delete_vdev;
 
 	/*
 	 * Add the toplevel vdev to the pool if its not already there.
@@ -1114,7 +1153,8 @@
 		vdev->v_state = VDEV_STATE_HEALTHY;
 	} else {
 		printf("ZFS: inconsistent nvlist contents\n");
-		return (EIO);
+		rc = EIO;
+		goto err_delete_vdev;
 	}
 
 	/*
@@ -1158,10 +1198,38 @@
 	}
 	zfs_free(upbuf, VDEV_UBERBLOCK_SIZE(vdev));
 
-	vdev->spa = spa;
-	if (spap != NULL)
-		*spap = spa;
-	return (0);
+	/* check uberblock and return as soon as a valid dva is found */
+	for (i = 0; i < SPA_DVAS_PER_BP; i++) {
+		const dva_t *const dva = &spa->spa_uberblock.ub_rootbp.blk_dva[i];
+
+		if (dva->dva_word[0] || dva->dva_word[1]) {
+			vdev->spa = spa;
+			if (spap != NULL)
+				*spap = spa;
+			return (0);
+		}
+	}
+
+	/* no uberblock with valid dva found */
+	rc = EIO;
+err_delete_vdev:
+	vdev_delete_by_guid(guid);
+err_delete_spa:
+	spa_delete_by_guid(pool_guid);
+	return (rc);
+}
+
+static int
+vdev_probe(vdev_phys_read_t *_read, void *read_priv, spa_t **spap)
+{
+	int tried_labels = 0; // this bitmask encodes tried labels
+	int err;
+
+	do {
+		err = vdev_probe_try(_read, read_priv, spap, &tried_labels);
+	} while (err && (tried_labels != ALL_LABELS_INVALID));
+
+	return (err);
 }
 
 static int