A slave node in your cluster has four 2TB hard drives installed (4 x 2TB). The DataNode is
configured to store HDFS blocks on the disks. You set the value of the
dfs.datanode.du.reserved parameter to 100GB. How does this alter HDFS block storage?

Your cluster is running MapReduce vserion 2 (MRv2) on YARN. Your ResourceManager is
configured to use the FairScheduler. Now you want to configure your scheduler such that a
new user on the cluster can submit jobs into their own queue application submission. Which
configuration should you set?

A user comes to you, complaining that when she attempts to submit a Hadoop job, it fails.
There is a directory in HDFS named /data/input. The Jar is named j.jar, and the driver class
is named DriverClass. She runs command: hadoop jar j.jar DriverClass
/data/input/data/output The error message returned includes the line:
PrivilegedActionException as:training (auth:SIMPLE)
cause.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exits:
file :/data/input What is the cause of the error?

In CDH4 and later, which file contains a serialized form of all the directory and files inodes in
the filesystem, giving the NameNode a persistent checkpoint of the filesystem metadata?

Which process instantiates user code, and executes map and reduce tasks on a cluster
running MapReduce V2 (MRv2) on YARN?

You are migrating a cluster from MapReduce version 1 (MRv1) to MapReduce version2
(MRv2) on YARN. To want to maintain your MRv1 TaskTracker slot capacities when you
migrate. What should you do?