Which of the following commands does Hadoop offer to discover missing or corrupt HDFS data?
A.
Hadoop does not provide any tools to discover missing or corrupt data; there is no need
because three replicas are kept for each data block.
B.
dskchk
C.
du
D.
fsck
E.
The map-only checksum utility.
Explanation:
http://docs.hortonworks.com/CURRENT/index.htm#Monitoring_HDP/Using_Nagios_With_Hadoop/
Nagios_Alerts_For_Hadoop_Services.htm (Corrupt/missing block alert, Possible remedies, third
bulleted point)