--- a/usr/src/uts/common/fs/zfs/spa_config.c	Sun May 20 02:46:39 2012 -0500
+++ b/usr/src/uts/common/fs/zfs/spa_config.c	Mon May 21 12:11:39 2012 -0700
@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 #include <sys/spa.h>
@@ -35,6 +35,7 @@
 #include <sys/utsname.h>
 #include <sys/systeminfo.h>
 #include <sys/sunddi.h>
+#include <sys/zfeature.h>
 #ifdef _KERNEL
 #include <sys/kobj.h>
 #include <sys/zone.h>
@@ -409,6 +410,12 @@
 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
 	nvlist_free(nvroot);
 
+	/*
+	 * Store what's necessary for reading the MOS in the label.
+	 */
+	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
+	    spa->spa_label_features) == 0);
+
 	if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) {
 		ddt_histogram_t *ddh;
 		ddt_stat_t *dds;