Hi Michalis: I solved this by re-run the command:  sudo /opt/cloudera/cm/schema/scm_prepare_database.sh mysql scm scm mypassword   This problem is due to my misunderstanding for scm_prepare_database.sh.   Thanks a lot for your help.   Kind regards ... View more

Hi Vijaya,   Under-replicated blocks are the blocks which does not meet the target replication factor. HDFS has self healing mechanism wherein it will create new replicas of under-replicated blocks until they meet the target replication.  if multi node cluster then you can verify if any datanodes are down  Or if it is one node cluster then please ensure replication factor is set to 1.    Thanks. ... View more