Hi Cloudera support team,    We're trying to increase available disk space in our cluster by decreasing a replication factor from 3 to 2 for some of the HDFS directories using the "hdfs dfs -setrep" command. I have a few questions:   How to estimate how much time would this command take for a single directory (without -w)? Will it trigger a replication job even if I don't use the '-w' flag? If yes, does it mean that the NameNode will actually start deleting 'over-replicated' blocks of all existing files under a particular directory?   Thank you  ... View more