Cloudera Docs

Replace a disk on a DataNode host

You must stop all the managed services and decommission the DataNode role instance before replacing any faulty disk on the DataNode host.

  1. Stop managed services.
  2. Decommission the DataNode role instance.
  3. Replace the failed disk.
  4. Recommission the DataNode role instance.
  5. Run the HDFS fsck utility to validate the health of HDFS.
    The utility normally reports over-replicated blocks immediately after a DataNode is reintroduced to the cluster, which is automatically corrected over time.
  6. Start managed services.