diff --git a/src/inc/taoserror.h b/src/inc/taoserror.h
index 67e2d43c98c11a24e348b5102377367024fa0286..17b2d24e909ff1a62f7c14b7ec658626b6deb159 100644
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@@ -246,6 +246,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_SYN_NOT_ENABLED,              0, 0x0901, "Sync modul
 
 // wal
 TAOS_DEFINE_ERROR(TSDB_CODE_WAL_APP_ERROR,                0, 0x1000, "Unexpected generic error in wal")
+TAOS_DEFINE_ERROR(TSDB_CODE_WAL_FILE_CORRUPTED,           0, 0x1001, "WAL file is corrupted")
 
 // http
 TAOS_DEFINE_ERROR(TSDB_CODE_HTTP_SERVER_OFFLINE,          0, 0x1100, "http server is not onlin")
diff --git a/src/mnode/src/mnodeSdb.c b/src/mnode/src/mnodeSdb.c
index 646c17b2b8b64344afb7c5117f2bd83b3da89dab..4c672eb557427d76f0989a4d8975eb7f7856c39e 100644
--- a/src/mnode/src/mnodeSdb.c
+++ b/src/mnode/src/mnodeSdb.c
@@ -185,7 +185,11 @@ static int32_t sdbInitWal() {
   }
 
   sdbInfo("open sdb wal for restore");
-  walRestore(tsSdbObj.wal, NULL, sdbWrite);
+  int code = walRestore(tsSdbObj.wal, NULL, sdbWrite);
+  if (code != TSDB_CODE_SUCCESS) {
+    sdbError("failed to open wal for restore, reason:%s", tstrerror(code));
+    return -1;
+  }
   return 0;
 }
 
diff --git a/src/wal/src/walMain.c b/src/wal/src/walMain.c
index bebad69f3224e70efb795dad51e77745ea3053e4..4987ba211667f60bc7a0ece60fc569768fd89256 100644
--- a/src/wal/src/walMain.c
+++ b/src/wal/src/walMain.c
@@ -347,9 +347,10 @@ static void walRelease(SWal *pWal) {
 
 static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
   char *name = pWal->name;
+  int size = 1024 * 1024; // default 1M buffer size
 
   terrno = 0;
-  char *buffer = malloc(1024000);  // size for one record
+  char *buffer = malloc(size);
   if (buffer == NULL) {
     terrno = TAOS_SYSTEM_ERROR(errno);   
     return terrno;
@@ -357,7 +358,7 @@ static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
 
   SWalHead *pHead = (SWalHead *)buffer;
 
-  int fd = open(name, O_RDONLY);
+  int fd = open(name, O_RDWR);
   if (fd < 0) {
     wError("wal:%s, failed to open for restore(%s)", name, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -367,29 +368,58 @@ static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
 
   wDebug("wal:%s, start to restore", name);
 
+  size_t offset = 0;
   while (1) {
     int ret = taosTRead(fd, pHead, sizeof(SWalHead));
-    if ( ret == 0)  break;  
+    if (ret == 0) break;
 
-    if (ret != sizeof(SWalHead)) {
-      wWarn("wal:%s, failed to read head, skip, ret:%d(%s)", name, ret, strerror(errno));
+    if (ret < 0) {
+      wError("wal:%s, failed to read wal head part since %s", name, strerror(errno));
       terrno = TAOS_SYSTEM_ERROR(errno);
       break;
     }
 
+    if (ret < sizeof(SWalHead)) {
+      wError("wal:%s, failed to read head, ret:%d, skip the rest of file", name, ret);
+      taosFtruncate(fd, offset);
+      fsync(fd);
+      break;
+    }
+
     if (!taosCheckChecksumWhole((uint8_t *)pHead, sizeof(SWalHead))) {
       wWarn("wal:%s, cksum is messed up, skip the rest of file", name);
-      terrno = TAOS_SYSTEM_ERROR(errno);
+      terrno = TSDB_CODE_WAL_FILE_CORRUPTED;
+      ASSERT(false);
       break;
-    } 
+    }
+
+    if (pHead->len > size - sizeof(SWalHead)) {
+      size = sizeof(SWalHead) + pHead->len;
+      buffer = realloc(buffer, size);
+      if (buffer == NULL) {
+        terrno = TAOS_SYSTEM_ERROR(errno);
+        break;
+      }
+
+      pHead = (SWalHead *)buffer;
+    }
 
     ret = taosTRead(fd, pHead->cont, pHead->len);
-    if ( ret != pHead->len) {
-      wWarn("wal:%s, failed to read body, skip, len:%d ret:%d", name, pHead->len, ret);
+    if (ret < 0) {
+      wError("wal:%s failed to read wal body part since %s", name, strerror(errno));
       terrno = TAOS_SYSTEM_ERROR(errno);
       break;
     }
 
+    if (ret < pHead->len) {
+      wError("wal:%s, failed to read body, len:%d ret:%d, skip the rest of file", name, pHead->len, ret);
+      taosFtruncate(fd, offset);
+      fsync(fd);
+      break;
+    }
+
+    offset = offset + sizeof(SWalHead) + pHead->len;
+
     if (pWal->keep) pWal->version = pHead->version;
     (*writeFp)(pVnode, pHead, TAOS_QTYPE_WAL);
   }