diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c
--- a/sys/dev/md/md.c
+++ b/sys/dev/md/md.c
@@ -1297,6 +1297,7 @@
 {
 	struct g_geom *gp;
 	struct g_provider *pp;
+	unsigned remn;
 
 	g_topology_lock();
 	gp = g_new_geomf(&g_md_class, "md%d", sc->unit);
@@ -1305,6 +1306,13 @@
 	devstat_remove_entry(pp->stat);
 	pp->stat = NULL;
 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
+	/* Prune off any residual fractional sector. */
+	remn = sc->mediasize % sc->sectorsize;
+	if (remn != 0) {
+		printf("md%d: truncating fractional last sector by %u bytes\n",
+		    sc->unit, remn);
+		sc->mediasize -= remn;
+	}
 	pp->mediasize = sc->mediasize;
 	pp->sectorsize = sc->sectorsize;
 	switch (sc->type) {
@@ -1674,7 +1682,7 @@
 {
 	struct md_s *sc;
 	unsigned sectsize;
-	int error, i;
+	int error;
 
 	sx_assert(&md_sx, SA_XLOCKED);
 
@@ -1746,10 +1754,6 @@
 		return (error);
 	}
 
-	/* Prune off any residual fractional sector */
-	i = sc->mediasize % sc->sectorsize;
-	sc->mediasize -= i;
-
 	mdinit(sc);
 	return (0);
 }