diff --git a/source/dnode/mnode/impl/inc/mndDef.h b/source/dnode/mnode/impl/inc/mndDef.h
index 0f4839392e66212c951237582f8c035398694456..e86ab1c4480bd34e9f2046a80bfc233eb4ba0b8a 100644
--- a/source/dnode/mnode/impl/inc/mndDef.h
+++ b/source/dnode/mnode/impl/inc/mndDef.h
@@ -17,14 +17,16 @@
 #define _TD_MND_DEF_H_
 
 #include "os.h"
+
+#include "cJSON.h"
+#include "sync.h"
 #include "taosmsg.h"
+#include "thash.h"
 #include "tlog.h"
 #include "trpc.h"
 #include "ttimer.h"
-#include "thash.h"
-#include "cJSON.h"
+
 #include "mnode.h"
-#include "sync.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -41,10 +43,8 @@ extern int32_t mDebugFlag;
 #define mTrace(...) { if (mDebugFlag & DEBUG_TRACE) { taosPrintLog("MND ", mDebugFlag, __VA_ARGS__); }}
 
 typedef struct SClusterObj SClusterObj;
-typedef struct SDnodeObj   SDnodeObj;
 typedef struct SMnodeObj   SMnodeObj;
 typedef struct SAcctObj    SAcctObj;
-typedef struct SUserObj    SUserObj;
 typedef struct SDbObj      SDbObj;
 typedef struct SVgObj      SVgObj;
 typedef struct SFuncObj    SFuncObj;
@@ -119,7 +119,7 @@ typedef struct SClusterObj {
   int64_t updateTime;
 } SClusterObj;
 
-typedef struct SDnodeObj {
+typedef struct {
   int32_t    id;
   int64_t    createdTime;
   int64_t    updateTime;
@@ -178,7 +178,7 @@ typedef struct SAcctObj {
   SAcctInfo info;
 } SAcctObj;
 
-typedef struct SUserObj {
+typedef struct {
   char      user[TSDB_USER_LEN];
   char      pass[TSDB_PASSWORD_LEN];
   char      acct[TSDB_USER_LEN];
diff --git a/source/dnode/mnode/impl/src/mndDb.c b/source/dnode/mnode/impl/src/mndDb.c
index b638728647c277761febf3869dff438fb75d5c8f..2d1bfefc2808148417941e5890b855a0b8531c6e 100644
--- a/source/dnode/mnode/impl/src/mndDb.c
+++ b/source/dnode/mnode/impl/src/mndDb.c
@@ -65,7 +65,7 @@ int32_t mndInitDb(SMnode *pMnode) {
 void mndCleanupDb(SMnode *pMnode) {}
 
 static SSdbRaw *mndDbActionEncode(SDbObj *pDb) {
-  SSdbRaw *pRaw = sdbAllocRaw(SDB_DB, TSDB_DB_VER_NUM, sizeof(SDbObj));
+  SSdbRaw *pRaw = sdbAllocRaw(SDB_DB, TSDB_DB_VER_NUM, sizeof(SDbObj) + TSDB_DB_RESERVE_SIZE);
   if (pRaw == NULL) return NULL;
 
   int32_t dataPos = 0;
diff --git a/source/dnode/mnode/impl/src/mndDnode.c b/source/dnode/mnode/impl/src/mndDnode.c
index e00244d05c9b493b20ebf6464ed9ea925be42e6b..72be28d2b3e755479bce12f5062d50e9ad59433a 100644
--- a/source/dnode/mnode/impl/src/mndDnode.c
+++ b/source/dnode/mnode/impl/src/mndDnode.c
@@ -108,7 +108,7 @@ static int32_t mndCreateDefaultDnode(SMnode *pMnode) {
 }
 
 static SSdbRaw *mndDnodeActionEncode(SDnodeObj *pDnode) {
-  SSdbRaw *pRaw = sdbAllocRaw(SDB_DNODE, TSDB_DNODE_VER, sizeof(SDnodeObj));
+  SSdbRaw *pRaw = sdbAllocRaw(SDB_DNODE, TSDB_DNODE_VER, sizeof(SDnodeObj) + TSDB_DNODE_RESERVE_SIZE);
   if (pRaw == NULL) return NULL;
 
   int32_t dataPos = 0;
diff --git a/source/dnode/mnode/impl/src/mndUser.c b/source/dnode/mnode/impl/src/mndUser.c
index 6fb05653a50e0103f87f16f62c2f2ee391dc0cb3..2243f787b96e3e0cd8f40b43abd63d7e3bbbea14 100644
--- a/source/dnode/mnode/impl/src/mndUser.c
+++ b/source/dnode/mnode/impl/src/mndUser.c
@@ -20,7 +20,8 @@
 #include "mndTrans.h"
 #include "tkey.h"
 
-#define SDB_USER_VER 1
+#define TSDB_USER_VER 1
+#define TSDB_USER_RESERVE_SIZE 64
 
 static int32_t  mndCreateDefaultUsers(SMnode *pMnode);
 static SSdbRaw *mndUserActionEncode(SUserObj *pUser);
@@ -93,7 +94,7 @@ static int32_t mndCreateDefaultUsers(SMnode *pMnode) {
 }
 
 static SSdbRaw *mndUserActionEncode(SUserObj *pUser) {
-  SSdbRaw *pRaw = sdbAllocRaw(SDB_USER, SDB_USER_VER, sizeof(SUserObj));
+  SSdbRaw *pRaw = sdbAllocRaw(SDB_USER, TSDB_USER_VER, sizeof(SUserObj) + TSDB_USER_RESERVE_SIZE);
   if (pRaw == NULL) return NULL;
 
   int32_t dataPos = 0;
@@ -103,6 +104,7 @@ static SSdbRaw *mndUserActionEncode(SUserObj *pUser) {
   SDB_SET_INT64(pRaw, dataPos, pUser->createdTime)
   SDB_SET_INT64(pRaw, dataPos, pUser->updateTime)
   SDB_SET_INT8(pRaw, dataPos, pUser->superUser)
+  SDB_SET_RESERVE(pRaw, dataPos, TSDB_USER_RESERVE_SIZE)
   SDB_SET_DATALEN(pRaw, dataPos);
 
   return pRaw;
@@ -112,7 +114,7 @@ static SSdbRow *mndUserActionDecode(SSdbRaw *pRaw) {
   int8_t sver = 0;
   if (sdbGetRawSoftVer(pRaw, &sver) != 0) return NULL;
 
-  if (sver != SDB_USER_VER) {
+  if (sver != TSDB_USER_VER) {
     mError("failed to decode user since %s", terrstr());
     terrno = TSDB_CODE_SDB_INVALID_DATA_VER;
     return NULL;
@@ -129,6 +131,7 @@ static SSdbRow *mndUserActionDecode(SSdbRaw *pRaw) {
   SDB_GET_INT64(pRaw, pRow, dataPos, &pUser->createdTime)
   SDB_GET_INT64(pRaw, pRow, dataPos, &pUser->updateTime)
   SDB_GET_INT8(pRaw, pRow, dataPos, &pUser->superUser)
+  SDB_GET_RESERVE(pRaw, pRow, dataPos, TSDB_USER_RESERVE_SIZE)
 
   return pRow;
 }