I use a fresh install of CDH 5.5.2. In Cloudera Manager I see, that HDFS has a critical health issue. I have 1 NameNode and 1 DataNode in cluster.
Under-Replicated Blocks
578 under replicated blocks in the cluster. 580 total blocks in the
cluster. Percentage under replicated blocks: 99.66%. Critical
threshold: 40.00%
How should I fix this issue?
UPDATE: Cloudera Manager(CDH 5.0.2) -> HDFS -> Configuration -> View and Edit -> Service-Wide -> Replication -> Replication Factor (dfs.replication) -> 1 isn't working in this case.
Alexandr Eroshenko :
The new replication factor affects only new files. To change replication factor for existing files run in shell (on the node with hadoop entry point)\n\nhadoop fs -setrep -w <replication factor> -R /\n\n\nBut, only \"hdfs\" can write to / (\"hdfs\" is the superuser, not \"root\"). So, may be you will have to use this command:\n\nsudo -u hdfs hadoop fs -setrep -w <replication factor> -R /\n",
2017-04-24T14:41:57