1693 persistent 'comment' field for a zpool

@@ -19,10 +19,12 @@
  * CDDL HEADER END
  */
 
 /*
  * 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.
  */
 
 #include <sys/spa.h>
 #include <sys/spa_impl.h>
 #include <sys/nvpair.h>

@@ -343,10 +345,14 @@
             spa_state(spa)) == 0);
         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
             txg) == 0);
         VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
             spa_guid(spa)) == 0);
+        VERIFY(spa->spa_comment == NULL || nvlist_add_string(config,
+            ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0);
+
+
 #ifdef  _KERNEL
         hostid = zone_get_hostid(NULL);
 #else   /* _KERNEL */
         /*
          * We're emulating the system's hostid in userland, so we can't use