diff --git a/source/dnode/mnode/impl/src/mndDb.c b/source/dnode/mnode/impl/src/mndDb.c
index 85b7fbbb42..bc4d890257 100644
--- a/source/dnode/mnode/impl/src/mndDb.c
+++ b/source/dnode/mnode/impl/src/mndDb.c
@@ -740,7 +740,7 @@ static int32_t mndBuildDropVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *
     if (pReq == NULL) return -1;
 
     action.pCont = pReq;
-    action.contLen = sizeof(SCreateVnodeReq);
+    action.contLen = sizeof(SDropVnodeReq);
     action.msgType = TDMT_DND_DROP_VNODE;
     action.acceptableCode = TSDB_CODE_DND_VNODE_NOT_DEPLOYED;
     if (mndTransAppendRedoAction(pTrans, &action) != 0) {
diff --git a/source/dnode/mnode/impl/src/mndDnode.c b/source/dnode/mnode/impl/src/mndDnode.c
index 4bc570c11d..2a67e6a0f9 100644
--- a/source/dnode/mnode/impl/src/mndDnode.c
+++ b/source/dnode/mnode/impl/src/mndDnode.c
@@ -235,7 +235,7 @@ int32_t mndGetDnodeSize(SMnode *pMnode) {
 
 bool mndIsDnodeOnline(SMnode *pMnode, SDnodeObj *pDnode, int64_t curMs) {
   int64_t interval = ABS(pDnode->lastAccessTime - curMs);
-  if (interval > 3500 * pMnode->cfg.statusInterval) {
+  if (interval > 10000 * pMnode->cfg.statusInterval) {
     if (pDnode->rebootTime > 0) {
       pDnode->offlineReason = DND_REASON_STATUS_MSG_TIMEOUT;
     }
diff --git a/source/dnode/mnode/impl/src/mndVgroup.c b/source/dnode/mnode/impl/src/mndVgroup.c
index e0d6d3dd42..93d6d104ff 100644
--- a/source/dnode/mnode/impl/src/mndVgroup.c
+++ b/source/dnode/mnode/impl/src/mndVgroup.c
@@ -319,6 +319,14 @@ static int32_t mndGetAvailableDnode(SMnode *pMnode, SVgObj *pVgroup, SArray *pAr
 
   taosArraySort(pArray, (__compar_fn_t)mndCompareDnodeVnodes);
 
+  int32_t size = taosArrayGetSize(pArray);
+  if (size < pVgroup->replica) {
+    mError("db:%s, vgId:%d, no enough online dnodes:%d to alloc %d replica", pVgroup->dbName, pVgroup->vgId, size,
+           pVgroup->replica);
+    terrno = TSDB_CODE_MND_NO_ENOUGH_DNODES;
+    return -1;
+  }
+
   for (int32_t v = 0; v < pVgroup->replica; ++v) {
     SVnodeGid *pVgid = &pVgroup->vnodeGid[v];
     SDnodeObj *pDnode = taosArrayGet(pArray, v);
diff --git a/tests/script/sh/exec.sh b/tests/script/sh/exec.sh
index 2e95a740d0..05f756ebb6 100755
--- a/tests/script/sh/exec.sh
+++ b/tests/script/sh/exec.sh
@@ -30,7 +30,7 @@ do
       CLEAR_OPTION="clear"
       ;;
     v)
-      SHELL_OPTION="true"
+      VALGRIND_OPTION="true"
       ;;
     u)
       USERS=$OPTARG
@@ -99,7 +99,7 @@ fi
 if [ "$EXEC_OPTON" = "start" ]; then 
   echo "ExcuteCmd:" $EXE_DIR/taosd -c $CFG_DIR
   
-  if [ "$SHELL_OPTION" = "true" ]; then 
+  if [ "$VALGRIND_OPTION" = "true" ]; then 
     TT=`date +%s`
     mkdir ${LOG_DIR}/${TT}
     nohup valgrind --log-file=${LOG_DIR}/${TT}/valgrind.log --tool=memcheck --leak-check=full --show-reachable=no  --track-origins=yes --show-leak-kinds=all  -v  --workaround-gcc296-bugs=yes   $EXE_DIR/taosd -c $CFG_DIR > /dev/null 2>&1 &   
diff --git a/tests/script/sim/db/basic6.sim b/tests/script/sim/db/basic6.sim
index 684ce825fe..8e7d4f5ec1 100644
--- a/tests/script/sim/db/basic6.sim
+++ b/tests/script/sim/db/basic6.sim
@@ -1,29 +1,24 @@
 system sh/stop_dnodes.sh
 system sh/deploy.sh -n dnode1 -i 1
-system sh/cfg.sh -n dnode1 -c wallevel -v 0
-system sh/cfg.sh -n dnode1 -c maxVgroupsPerDb -v 4
-system sh/cfg.sh -n dnode1 -c maxTablesPerVnode -v 1000
-
 system sh/exec.sh -n dnode1 -s start
-
-sleep 2000
 sql connect
+
 print ============================ dnode1 start
 
 $i = 0
-$dbPrefix = ob_db_db
-$tbPrefix = ob_db_tb
+$dbPrefix = db
+$tbPrefix = tb
 $db = $dbPrefix . $i
 $tb = $tbPrefix . $i
 
 print =============== step1
-sql create database $db replica 1 days 20 keep 2000 cache 16
+sql create database $db replica 1 days 20 keep 2000 cache 16 vgroups 4
 sql show databases
 print $data00 $data01 $data02 $data03 $data04 $data05 $data06 $data07
 if $data00 != $db then 
   return -1
 endi
-if $data02 != 0 then 
+if $data02 != 4 then 
   return -1
 endi
 if $data03 != 0 then 
@@ -63,9 +58,6 @@ print $data00 $data01 $data02 $data03 $data04 $data05 $data06 $data07
 if $data00 != $db then 
   return -1
 endi
-if $data02 != 0 then 
-  return -1
-endi
 if $data03 != 0 then 
   return -1
 endi
@@ -77,30 +69,14 @@ if $data06 != 15 then
 endi
 
 print =============== step6
-sql use $db
-sql create table $tb (ts timestamp, speed int)
-$i = 1
-while $i < 4
+$i = $i + 1
+while $i < 5
   $db = $dbPrefix . $i
-  $tb = $tbPrefix . $i
   sql create database $db
   sql use $db
-  sql create table $tb (ts timestamp, speed int)
   $i = $i + 1
 endw
 
-sql show databases
-if $rows != 4 then 
-  return -1
-endi
-
-$i = 4
-$db = $dbPrefix . $i
-$tb = $tbPrefix . $i
-sql create database $db
-sql use $db
-sql create table $tb (ts timestamp, speed int)
-
 print =============== step7
 $i = 0
 while $i < 5
@@ -115,7 +91,8 @@ $db = $dbPrefix . $i
 $tb = $tbPrefix . $i
 sql create database $db
 sql use $db
-sql create table $tb (ts timestamp, speed int)
+sql create table st (ts timestamp, i int) tags (j int)
+sql create table $tb using st tags(1)
 sql show tables
 if $rows != 1 then 
   return -1
@@ -133,7 +110,8 @@ if $rows != 0 then
 endi
 
 print =============== step11
-sql create table $tb (ts timestamp, speed int)
+sql create table st (ts timestamp, i int) tags (j int)
+sql create table $tb using st tags(1)
 sql show tables
 if $rows != 1 then 
   return -1
@@ -149,16 +127,23 @@ sql show tables
 if $rows != 0 then 
   return -1
 endi
-sql create table $tb (ts timestamp, speed int)
+
+sql create table st (ts timestamp, i int) tags (j int)
+sql create table $tb using st tags(1)
 sql show tables
 if $rows != 1 then 
   return -1
 endi
+
 sql insert into $tb values (now+1a, 0)
 sql insert into $tb values (now+2a, 1)
 sql insert into $tb values (now+3a, 2)
 sql insert into $tb values (now+4a, 3)
 sql insert into $tb values (now+5a, 4)
+
+
+return 
+
 sql select * from $tb
 if $rows != 5 then 
   return -1
@@ -176,7 +161,8 @@ if $rows != 0 then
 endi
 
 print =============== step16
-sql create table $tb (ts timestamp, speed int)
+sql create table st (ts timestamp, i int) tags (j int)
+sql create table $tb using st tags(1)
 sql show tables
 if $rows != 1 then 
   return -1