diff --git a/pkg/compute/models/diskbackups.go b/pkg/compute/models/diskbackups.go
index a277c36afd..fc5d9d8584 100644
--- a/pkg/compute/models/diskbackups.go
+++ b/pkg/compute/models/diskbackups.go
@@ -18,6 +18,7 @@ import (
 	"context"
 	"database/sql"
 	"reflect"
+	"strings"
 	"time"
 
 	"yunion.io/x/jsonutils"
@@ -290,11 +291,26 @@ func (dm *SDiskBackupManager) ValidateCreateData(
 			return input, httperrors.NewNotFoundError("fetch container by %s", input.BackupAsTar.ContainerId)
 		}
 		input.BackupAsTar.ContainerId = ctr.GetId()
+		if err := dm.validateBackupAsTarFiles(input.BackupAsTar.IncludeFiles); err != nil {
+			return input, httperrors.NewInputParameterError("validate include_files: %s", err)
+		}
+		if err := dm.validateBackupAsTarFiles(input.BackupAsTar.ExcludeFiles); err != nil {
+			return input, httperrors.NewInputParameterError("validate exclude_files: %s", err)
+		}
 	}
 
 	return input, nil
 }
 
+func (dm *SDiskBackupManager) validateBackupAsTarFiles(paths []string) error {
+	for _, p := range paths {
+		if strings.HasPrefix(p, "/") {
+			return httperrors.NewInputParameterError("%s can't start with /", p)
+		}
+	}
+	return nil
+}
+
 func (db *SDiskBackup) CustomizeCreate(ctx context.Context, userCred mcclient.TokenCredential, ownerId mcclient.IIdentityProvider, query jsonutils.JSONObject, data jsonutils.JSONObject) error {
 	input := new(api.DiskBackupCreateInput)
 	if err := data.Unmarshal(input); err != nil {
diff --git a/pkg/hostman/guestman/pod.go b/pkg/hostman/guestman/pod.go
index 6449c88e5e..9ea661080d 100644
--- a/pkg/hostman/guestman/pod.go
+++ b/pkg/hostman/guestman/pod.go
@@ -1851,28 +1851,38 @@ func (s *sPodGuestInstance) DoSnapshot(ctx context.Context, params *SDiskSnapsho
 			return nil, errors.Wrapf(err, "bind mount %s to %s: %s", mntPath, targetBindMntPath, out)
 		}
 	}
+	deferUmount := func() error {
+		for _, vol := range vols {
+			// unbind mount
+			// umount
+			targetBindMntPath := filepath.Join(tmpBackRootDir, vol.Disk.SubDirectory)
+			if vol.Disk.StorageSizeFile != "" {
+				targetBindMntPath = filepath.Join(tmpBackRootDir, vol.Disk.StorageSizeFile)
+			}
+			out, err := procutils.NewRemoteCommandAsFarAsPossible("umount", targetBindMntPath).Output()
+			if err != nil {
+				return errors.Wrapf(err, "umount bind point %s: %s", targetBindMntPath, out)
+			}
+		}
+		for _, vol := range vols {
+			drv := volume_mount.GetDriver(vol.Type)
+			if err := drv.Unmount(s, input.ContainerId, vol); err != nil {
+				return errors.Wrapf(err, "unmount %s to %s", input.ContainerId, jsonutils.Marshal(vol))
+			}
+		}
+		return nil
+	}
+	defer func() {
+		if err := deferUmount(); err != nil {
+			log.Errorf("deferUmount after snapshot error: %s", err)
+		} else {
+			log.Infof("defer umount success")
+		}
+	}()
 	snapshotPath, err := s.createSnapshot(params, tmpBackRootDir)
 	if err != nil {
 		return nil, errors.Wrap(err, "create snapshot")
 	}
-	for _, vol := range vols {
-		// unbind mount
-		// umount
-		targetBindMntPath := filepath.Join(tmpBackRootDir, vol.Disk.SubDirectory)
-		if vol.Disk.StorageSizeFile != "" {
-			targetBindMntPath = filepath.Join(tmpBackRootDir, vol.Disk.StorageSizeFile)
-		}
-		out, err := procutils.NewRemoteCommandAsFarAsPossible("umount", targetBindMntPath).Output()
-		if err != nil {
-			return nil, errors.Wrapf(err, "umount bind point %s: %s", targetBindMntPath, out)
-		}
-	}
-	for _, vol := range vols {
-		drv := volume_mount.GetDriver(vol.Type)
-		if err := drv.Unmount(s, input.ContainerId, vol); err != nil {
-			return nil, errors.Wrapf(err, "unmount %s to %s", input.ContainerId, jsonutils.Marshal(vol))
-		}
-	}
 	res := jsonutils.NewDict()
 	res.Set("location", jsonutils.NewString(snapshotPath))
 	return res, nil