diff --git a/app/vmselect/netstorage/tmp_blocks_file.go b/app/vmselect/netstorage/tmp_blocks_file.go
index 7a278898f..947870023 100644
--- a/app/vmselect/netstorage/tmp_blocks_file.go
+++ b/app/vmselect/netstorage/tmp_blocks_file.go
@@ -85,7 +85,12 @@ func (addr tmpBlockAddr) String() string {
 	return fmt.Sprintf("offset %d, size %d", addr.offset, addr.size)
 }
 
-var tmpBlocksFilesCreated = metrics.NewCounter(`vm_tmp_blocks_files_created_total`)
+var (
+	tmpBlocksFilesCreated = metrics.NewCounter(`vm_tmp_blocks_files_created_total`)
+	_ = metrics.NewGauge(`vm_tmp_blocks_files_directory_free_bytes`, func() float64 {
+		return float64(fs.MustGetFreeSpace(tmpBlocksDir))
+	})
+)
 
 // WriteBlockData writes b to tbf.
 //