I was trying to copy files from cluster to another one using distcp tool, when HDFS was at safe mode but after use this statement "hadoop fs -safemode leave" clusterid in the data node was change, then I modify it manually. now the cluster working but I didn't find some directories in the HDFS (HDP 2.6)
How did the clusterid in the data node changed? clusterid is used to prevent DataNodes from registering accidentally with an incorrect NameNode that is part of a different cluster.
I think you have modified this, your data nodes think that this is a different name node and they are not registering.
I am confused about how clusterid on data node changed which led you to modify this value.