hdfs dfs -mkdir /tmp/mydirectory

-- put some files into your directory
hdfs dfs –put  important-file.txt  /tmp/mydirectory

-- Allowing smaphot for your directory
hdfs dfsadmin -allowSnapshot  /tmp/mydirectory

-- create a snapshot to your directory
hdfs dfs -createSnapshot /tmp/mydirectory  snapshot_one

-- Testing removing directory( snapshot directory cannot be removed)
hdfs dfs -rm -r -skipTrash /tmp/mydirectory

-- removing files from snapshot directory  (yes,  fles in dnapshot directory can be removed!!)
hdfs dfs -rm -r /tmp/mydirectory/somefile.ext

Recover the file from the snapshot
--list all the snapshot directory
hdfs lsSnapshottableDir

--First, find the file that you want to recover from in the snapshot subdirectory:
hdfs dfs –lsr –R /tmp/mydirectory/.snapshot

-- reading deleted file from snapshot
hdfs dfs -cat /tmp/mydirectory/.snapshot/snapshot_one/somefile.ext

--copy the file from snapshot to your directory (using cp command)
hdfs dfs -cp /tmp/mydirectory/.snapshot/snapshot_one/isomefile.ext /tmp/mydirectory