diff --git a/packaging/cfg/taos.cfg b/packaging/cfg/taos.cfg
index 310369aa14ad5e9e6ccb49843605a92fdc333563..33eca991265e2bbd32cb635b622f8133b66ebeb4 100644
--- a/packaging/cfg/taos.cfg
+++ b/packaging/cfg/taos.cfg
@@ -289,3 +289,6 @@ keepColumnName            1
 
 # percent of redundant data in tsdb meta will compact meta data,0 means donot compact
 # tsdbMetaCompactRatio    0
+
+# unit MB. Flush vnode wal file if walSize > walFlushSize and walSize > cache*0.5*blocks
+# walFlushSize         1024
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 1b6d94440ccbf56b0f77cafd3a8add9fdf9211a4..c2e3d426a07a17286bfd0ed83e800e4a891d2ef7 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -1652,7 +1652,7 @@ static void doInitGlobalConfig(void) {
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
 
-  // flush vnode wal file if walSize >= walFlushSize and walSize >= cache*blocks*0.5
+  // flush vnode wal file if walSize > walFlushSize and walSize > cache*0.5*blocks
   cfg.option = "walFlushSize";
   cfg.ptr = &tsdbWalFlushSize;
   cfg.valType = TAOS_CFG_VTYPE_INT32;