diff --git a/cdc/kv/etcd_test.go b/cdc/kv/etcd_test.go
index 10059635adc..569a7953c3f 100644
--- a/cdc/kv/etcd_test.go
+++ b/cdc/kv/etcd_test.go
@@ -225,6 +225,7 @@ func (s *etcdSuite) TestOpChangeFeedDetail(c *check.C) {
 	ctx := context.Background()
 	detail := &model.ChangeFeedInfo{
 		SinkURI: "root@tcp(127.0.0.1:3306)/mysql",
+		SortDir: "/old-version/sorter",
 	}
 	cfID := "test-op-cf"
 
@@ -236,6 +237,7 @@ func (s *etcdSuite) TestOpChangeFeedDetail(c *check.C) {
 	d, err := s.client.GetChangeFeedInfo(ctx, cfID)
 	c.Assert(err, check.IsNil)
 	c.Assert(d.SinkURI, check.Equals, detail.SinkURI)
+	c.Assert(d.SortDir, check.Equals, detail.SortDir)
 
 	err = s.client.LeaseGuardDeleteChangeFeedInfo(ctx, cfID, sess.Lease())
 	c.Assert(err, check.IsNil)
diff --git a/cdc/model/changefeed.go b/cdc/model/changefeed.go
index 444dce38095..d8bcb48230b 100644
--- a/cdc/model/changefeed.go
+++ b/cdc/model/changefeed.go
@@ -78,7 +78,9 @@ type ChangeFeedInfo struct {
 	AdminJobType AdminJobType `json:"admin-job-type"`
 	Engine       SortEngine   `json:"sort-engine"`
 	// SortDir is deprecated
-	SortDir string `json:"-"`
+	// it cannot be set by user in changefeed level, any assignment to it should be ignored.
+	// but can be fetched for backward compatibility
+	SortDir string `json:"sort-dir"`
 
 	Config   *config.ReplicaConfig `json:"config"`
 	State    FeedState             `json:"state"`
diff --git a/cdc/model/changefeed_test.go b/cdc/model/changefeed_test.go
index c58bf67343f..ff7f0a3e2b4 100644
--- a/cdc/model/changefeed_test.go
+++ b/cdc/model/changefeed_test.go
@@ -120,6 +120,7 @@ func (s *configSuite) TestFillV1(c *check.C) {
 		},
 		StartTs: 417136892416622595,
 		Engine:  "memory",
+		SortDir: ".",
 		Config: &config.ReplicaConfig{
 			CaseSensitive: true,
 			Filter: &config.FilterConfig{
diff --git a/cdc/server.go b/cdc/server.go
index 4a5747d1232..c4849c40eb0 100644
--- a/cdc/server.go
+++ b/cdc/server.go
@@ -375,10 +375,8 @@ func (s *Server) initDataDir(ctx context.Context) error {
 		return errors.Trace(err)
 	}
 
-	if diskInfo.Avail < dataDirThreshold {
-		log.Warn(fmt.Sprintf("%s is set as data-dir (%dGB available), ticdc recommend disk for data-dir "+
-			"at least have %dGB available space", conf.DataDir, diskInfo.Avail, dataDirThreshold))
-	}
+	log.Info(fmt.Sprintf("%s is set as data-dir (%dGB available), ticdc recommend disk for data-dir "+
+		"at least have %dGB available space", conf.DataDir, diskInfo.Avail, dataDirThreshold))
 
 	return nil
 }
@@ -441,14 +439,25 @@ func (s *Server) setUpDataDir(ctx context.Context) error {
 // at the moment, only consider available disk space
 func findBestDataDir(candidates []string) (result string, ok bool) {
 	var low uint64 = 0
-	for _, dir := range candidates {
+
+	checker := func(dir string) (*util.DiskInfo, error) {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return nil, err
+		}
 		if err := util.IsDirReadWritable(dir); err != nil {
-			log.Warn("try to get disk info failed", zap.String("dir", dir), zap.Error(err))
-			continue
+			return nil, err
 		}
 		info, err := util.GetDiskInfo(dir)
 		if err != nil {
-			log.Warn("try to get disk info failed", zap.String("dir", dir), zap.Error(err))
+			return nil, err
+		}
+		return info, err
+	}
+
+	for _, dir := range candidates {
+		info, err := checker(dir)
+		if err != nil {
+			log.Warn("check the availability of dir", zap.String("dir", dir), zap.Error(err))
 			continue
 		}
 		if info.Avail > low {