HDFS-7710. Remove dead code in BackupImage.java. Contributed by Xiaoyu Yao.

(cherry picked from commit cfb829ecd5)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -301,6 +301,8 @@ Release 2.7.0 - UNRELEASED
     HDFS-7732. Fix the order of the parameters in DFSConfigKeys.
     (Brahma Reddy Battula via aajisaka)
 
+    HDFS-7710. Remove dead code in BackupImage.java. (Xiaoyu Yao via aajisaka)
+
   OPTIMIZATIONS
 
     HDFS-7454. Reduce memory footprint for AclEntries in NameNode.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/BackupImage.java

@@ -140,14 +140,6 @@ public class BackupImage extends FSImage {
     }
   }
 
-  /**
-   * Save meta-data into fsimage files.
-   * and create empty edits.
-   */
-  void saveCheckpoint() throws IOException {
-    saveNamespace(namesystem);
-  }
-
   /**
    * Receive a batch of edits from the NameNode.
    *