diff --git a/sys/geom/mirror/g_mirror.c b/sys/geom/mirror/g_mirror.c
index 51836b7eabb..c0641d15673 100644
--- a/sys/geom/mirror/g_mirror.c
+++ b/sys/geom/mirror/g_mirror.c
@@ -749,6 +749,7 @@ g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
     struct g_mirror_metadata *md)
 {
 
+	bzero(md, sizeof(*md));
 	strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
 	md->md_version = G_MIRROR_VERSION;
 	strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
@@ -760,14 +761,8 @@ g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
 	md->md_mediasize = sc->sc_mediasize;
 	md->md_sectorsize = sc->sc_sectorsize;
 	md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
-	bzero(md->md_provider, sizeof(md->md_provider));
 	if (disk == NULL) {
 		md->md_did = arc4random();
-		md->md_priority = 0;
-		md->md_syncid = 0;
-		md->md_dflags = 0;
-		md->md_sync_offset = 0;
-		md->md_provsize = 0;
 	} else {
 		md->md_did = disk->d_id;
 		md->md_priority = disk->d_priority;
@@ -775,8 +770,6 @@ g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
 		md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
 		if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 			md->md_sync_offset = disk->d_sync.ds_offset_done;
-		else
-			md->md_sync_offset = 0;
 		if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
 			strlcpy(md->md_provider,
 			    disk->d_consumer->provider->name,
diff --git a/sys/geom/mirror/g_mirror_ctl.c b/sys/geom/mirror/g_mirror_ctl.c
index 254841b6c04..355504a6f90 100644
--- a/sys/geom/mirror/g_mirror_ctl.c
+++ b/sys/geom/mirror/g_mirror_ctl.c
@@ -747,7 +747,7 @@ again:
 			bzero(md.md_provider, sizeof(md.md_provider));
 		}
 		md.md_provsize = pp->mediasize;
-		sector = g_malloc(pp->sectorsize, M_WAITOK);
+		sector = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
 		mirror_metadata_encode(&md, sector);
 		error = g_write_data(disks[i].consumer,
 		    pp->mediasize - pp->sectorsize, sector, pp->sectorsize);