HDFS-8706. Fix typo in datanode startup options in HDFSCommands.html. (Controibuted by Brahma Reddy Battula)

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

@@ -656,6 +656,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-8579. Update HDFS usage with missing options
     (J.Andreina via vinayakumarb)
 
+    HDFS-8706. Fix typo in datanode startup options in HDFSCommands.html.
+    (Brahma Reddy Battula via Arpit Agarwal)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSCommands.md

@@ -297,7 +297,7 @@ See the [HDFS Transparent Encryption Documentation](./TransparentEncryption.html
 
 ### `datanode`
 
-Usage: `hdfs datanode [-regular | -rollback | -rollingupgrace rollback]`
+Usage: `hdfs datanode [-regular | -rollback | -rollingupgrade rollback]`
 
 | COMMAND\_OPTION | Description |
 |:---- |:---- |