diff --git a/pkg/manager/service.go b/pkg/manager/service.go
index 23fcaa92..6f51c87f 100644
--- a/pkg/manager/service.go
+++ b/pkg/manager/service.go
@@ -304,13 +304,18 @@ func (m *Manager) Sync(ctx context.Context, req *rpc.SyncRequest) (resp *rpc.Bac
 	if err != nil {
 		return nil, err
 	}
-	portReleaseChannel := make(chan interface{})
+	portReleaseChannel := make(chan interface{}, 1)
 	go func() {
 		<-portReleaseChannel
+		log.Infof("Backing Image Manager: start to release port %v after syncing", port)
+		if !util.DetectHTTPServerAvailability(fmt.Sprintf("http://localhost:%d", port), 180, false) {
+			log.Errorf("Backing Image Manager: failed to wait for the HTTP server using port %v stopped, cannot release the port", port)
+			return
+		}
 		if err := m.releasePorts(port, port+1); err != nil {
 			log.WithError(err).Errorf("Backing Image Manager: failed to release port %v after syncing backing image", port)
 		}
-
+		log.Infof("Backing Image Manager: released port %v after syncing", port)
 	}()
 
 	biFilePath := types.GetBackingImageFilePath(m.diskPath, req.Spec.Name, req.Spec.Uuid)
@@ -320,56 +325,85 @@ func (m *Manager) Sync(ctx context.Context, req *rpc.SyncRequest) (resp *rpc.Bac
 	}
 
 	go func() {
+		var biResp *rpc.BackingImageResponse
+
 		defer func() {
-			portReleaseChannel <- nil
 			if err != nil {
+				portReleaseChannel <- nil
 				log.WithError(err).Error("Backing Image Manager: failed to request sending the backing image")
+				return
 			}
+
+			// Wait for 24 hours
+			if biResp, err = m.waitForEndingFileState(req.Spec.Name, req.Spec.Uuid, 24*60*60); err != nil {
+				log.WithError(err).Errorf("Backing Image Manager: timeout waiting before releasing port %v", port)
+			}
+			portReleaseChannel <- nil
 		}()
 
-		var biFileInfo *api.FileInfo
-		if biFileInfo, err = m.waitForFileStateNonPending(req.Spec.Name, 300); err != nil {
+		if biResp, err = m.waitForFileStateNonPending(req.Spec.Name, req.Spec.Uuid, 300); err != nil {
 			return
 		}
-		if biFileInfo.State != string(types.StateStarting) {
-			log.Infof("Backing Image Manager: there is no need to request backing image since the current state is %v rather than %v", biFileInfo.State, types.StateStarting)
+		if biResp.Status.State != string(types.StateStarting) {
+			err = fmt.Errorf("there is no need to request backing image since the current state is %v rather than %v", biResp.Status.State, types.StateStarting)
 			return
 		}
 
-		receiverIP, err := util.GetIPForPod()
+		toIP, err := util.GetIPForPod()
 		if err != nil {
 			return
 		}
-		toAddress := fmt.Sprintf("%s:%d", receiverIP, port)
+		toAddress := fmt.Sprintf("%s:%d", toIP, port)
 
+		// sender.Send is a non-blocking call
 		sender := client.NewBackingImageManagerClient(req.FromAddress)
 		if err = sender.Send(req.Spec.Name, req.Spec.Uuid, toAddress); err != nil {
-			err = errors.Wrapf(err, "sender failed to request backing image sending")
+			err = errors.Wrapf(err, "sender failed to request backing image sending to %v", toAddress)
 			return
 		}
 
 		log.Infof("Backing Image Manager: started requesting sending backing image from address %v to address %v", req.FromAddress, toAddress)
 	}()
 
-	log.Info("Backing Image Manager: started receiving backing image")
+	log.Infof("Backing Image Manager: started receiving backing image at port %v", port)
 
 	return m.getAndUpdate(req.Spec.Name, req.Spec.Uuid)
 }
 
-func (m *Manager) waitForFileStateNonPending(name string, waitInterval int) (biFileInfo *api.FileInfo, err error) {
+func (m *Manager) waitForFileStateNonPending(name, uuid string, waitInterval int) (biResp *rpc.BackingImageResponse, err error) {
 	endTime := time.Now().Add(time.Duration(waitInterval) * time.Second)
+
 	ticker := time.NewTicker(time.Second)
 	defer ticker.Stop()
 	for time.Now().Before(endTime) {
 		<-ticker.C
-		m.lock.RLock()
-		biFileInfo = m.biFileInfoMap[name]
-		m.lock.RUnlock()
-		if biFileInfo != nil && biFileInfo.State != string(types.StatePending) {
-			return biFileInfo, nil
+		if biResp, _ = m.getAndUpdate(name, uuid); biResp != nil && biResp.Status.State != string(types.StatePending) {
+			return biResp, nil
+		}
+	}
+
+	return nil, fmt.Errorf("failed to wait for backing image %v(%v) becoming state non-pending", name, uuid)
+}
+
+func (m *Manager) waitForEndingFileState(name, uuid string, waitInterval int) (biResp *rpc.BackingImageResponse, err error) {
+	endTime := time.Now().Add(time.Duration(waitInterval) * time.Second)
+
+	ticker := time.NewTicker(types.MonitorInterval)
+	defer ticker.Stop()
+	for time.Now().Before(endTime) {
+		<-ticker.C
+		biResp, err = m.getAndUpdate(name, uuid)
+		if util.IsGRPCErrorNotFound(err) ||
+			(biResp != nil && (biResp.Status.State == string(types.StateReady) || biResp.Status.State == string(types.StateFailed))) {
+			return biResp, nil
 		}
 	}
-	return nil, fmt.Errorf("failed to wait for backing image %v becoming state non-pending", name)
+
+	state := "unavailable"
+	if biResp != nil {
+		state = biResp.Status.State
+	}
+	return nil, fmt.Errorf("failed to wait for backing image %v(%v) becoming an ending state, current state %v", name, uuid, state)
 }
 
 func (m *Manager) Send(ctx context.Context, req *rpc.SendRequest) (resp *empty.Empty, err error) {
diff --git a/pkg/sync/sync_file.go b/pkg/sync/sync_file.go
index 4a7434e6..e5b29971 100644
--- a/pkg/sync/sync_file.go
+++ b/pkg/sync/sync_file.go
@@ -523,7 +523,7 @@ func (sf *SyncingFile) IdleTimeoutCopyToFile(src io.ReadCloser) (copied int64, e
 }
 
 func (sf *SyncingFile) Receive(port int, fileType string) (err error) {
-	sf.log.Infof("SyncingFile: start to launch a receiver")
+	sf.log.Infof("SyncingFile: start to launch a receiver at port %v", port)
 
 	needProcessing, err := sf.stateCheckBeforeProcessing()
 	if err != nil {
@@ -539,7 +539,8 @@ func (sf *SyncingFile) Receive(port int, fileType string) (err error) {
 
 	// TODO: After merging the sparse tool repo into this sync service, we don't need to launch a separate server here.
 	//  Instead, this SyncingFile is responsible for punching hole, reading/writing data, and computing checksum.
-	if err = sparserest.Server(sf.ctx, strconv.Itoa(port), sf.tmpFilePath, sf); err != nil && err != http.ErrServerClosed {
+	if serverErr := sparserest.Server(sf.ctx, strconv.Itoa(port), sf.tmpFilePath, sf); serverErr != nil && serverErr != http.ErrServerClosed {
+		err = serverErr
 		return err
 	}