diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index b13797ae06..436594ee3a 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -427,6 +427,8 @@ Release 2.6.0 - UNRELEASED
     HDFS-6797. DataNode logs wrong layoutversion during upgrade. (Benoy Antony
     via Arpit Agarwal)
 
+    HDFS-6810. StorageReport array is initialized with wrong size in
+    DatanodeDescriptor#getStorageReports. (szetszwo via Arpit Agarwal)
 Release 2.5.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java
index fcc189d9f9..d622905f0b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java
@@ -260,8 +260,8 @@ public class DatanodeDescriptor extends DatanodeInfo {
   }
 
   public StorageReport[] getStorageReports() {
-    final StorageReport[] reports = new StorageReport[storageMap.size()];
     final DatanodeStorageInfo[] infos = getStorageInfos();
+    final StorageReport[] reports = new StorageReport[infos.length];
     for(int i = 0; i < infos.length; i++) {
       reports[i] = infos[i].toStorageReport();
     }