Performing Disk Hot Swap for DataNodes

This section describes how to replace HDFS disks without shutting down a DataNode. This is referred to as hot swap.

Performing Disk Hot Swap for DataNodes Using Cloudera Manager

Minimum Required Role: Cluster Administrator (also provided by Full Administrator)

  1. Configure data directories to remove the disk you are swapping out:
    1. Go to the HDFS service.
    2. Click the Instances tab.
    3. In the Role Type column, click on the affected DataNode.
    4. Click the Configuration tab.
    5. Select Scope > DataNode.
    6. Select Category > Main.
    7. Change the value of the DataNode Data Directory property to remove the directories that are mount points for the disk you are removing.
  2. Enter a Reason for change, and then click Save Changes to commit the changes.
  3. Refresh the affected DataNode. Select Actions > Refresh DataNode configuration.
  4. Remove the old disk and add the replacement disk.
  5. Change the value of the DataNode Data Directory property to add back the directories that are mount points for the disk you added.
  6. Enter a Reason for change, and then click Save Changes to commit the changes.
  7. Refresh the affected DataNode. Select Actions > Refresh DataNode configuration.
  8. Run the HDFS fsck utility to validate the health of HDFS.