diff --git a/pkg/ddc/alluxio/operations/base.go b/pkg/ddc/alluxio/operations/base.go
index d29b65c4641..111f243ce5f 100644
--- a/pkg/ddc/alluxio/operations/base.go
+++ b/pkg/ddc/alluxio/operations/base.go
@@ -508,6 +508,7 @@ func (a AlluxioFileUtils) Mkdir(alluxioPath string) (err error) {
 	return
 }
 
+// Du returns UFS size, cached size, and cache percentage for a path by running `alluxio fs du -s`.
 func (a AlluxioFileUtils) Du(alluxioPath string) (ufs int64, cached int64, cachedPercentage string, err error) {
 	var (
 		command = []string{"alluxio", "fs", "du", "-s", alluxioPath}