diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index 63f2f3794..01758b0c5 100644
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -553,6 +553,7 @@ vdev_add_child(vdev_t *pvd, vdev_t *cvd)
 
 	pvd->vdev_child = newchild;
 	pvd->vdev_child[id] = cvd;
+	pvd->vdev_nonrot &= cvd->vdev_nonrot;
 
 	cvd->vdev_top = (pvd->vdev_top ? pvd->vdev_top: cvd);
 	ASSERT(cvd->vdev_top->vdev_parent->vdev_parent == NULL);
@@ -1374,6 +1375,7 @@ vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops)
 	mvd->vdev_physical_ashift = cvd->vdev_physical_ashift;
 	mvd->vdev_state = cvd->vdev_state;
 	mvd->vdev_crtxg = cvd->vdev_crtxg;
+	mvd->vdev_nonrot = cvd->vdev_nonrot;
 
 	vdev_remove_child(pvd, cvd);
 	vdev_add_child(pvd, mvd);
@@ -1579,6 +1581,18 @@ vdev_metaslab_init(vdev_t *vd, uint64_t txg)
 	vd->vdev_ms = mspp;
 	vd->vdev_ms_count = newc;
 
+	/*
+	 * Weighting algorithms can depend on the number of metaslabs in the
+	 * vdev. In order to ensure that all weights are correct at all times,
+	 * we need to recalculate here.
+	 */
+	for (uint64_t m = 0; m < oldc; m++) {
+		metaslab_t *msp = vd->vdev_ms[m];
+		mutex_enter(&msp->ms_lock);
+		metaslab_recalculate_weight_and_sort(msp);
+		mutex_exit(&msp->ms_lock);
+	}
+
 	for (uint64_t m = oldc; m < newc; m++) {
 		uint64_t object = 0;
 		/*
@@ -1960,6 +1974,10 @@ vdev_open_children_impl(vdev_t *vd, vdev_open_children_func_t *open_func)
 		taskq_wait(tq);
 	for (int c = 0; c < children; c++) {
 		vdev_t *cvd = vd->vdev_child[c];
+
+		if (open_func(cvd) == B_FALSE ||
+		    cvd->vdev_state <= VDEV_STATE_FAULTED)
+			continue;
 		vd->vdev_nonrot &= cvd->vdev_nonrot;
 	}
 
diff --git a/module/zfs/vdev_draid.c b/module/zfs/vdev_draid.c
index e0fafd0da..feec5fd3c 100644
--- a/module/zfs/vdev_draid.c
+++ b/module/zfs/vdev_draid.c
@@ -2484,6 +2484,7 @@ vdev_draid_spare_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
 	*max_psize = max_asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE;
 
 	vds->vds_draid_vdev = tvd;
+	vd->vdev_nonrot = tvd->vdev_nonrot;
 
 	return (0);
 }