Adjusting Parameters Related to Damaged DataNode Disk Volumes

Scenario

In the open-source HDFS, if multiple disk volumes are configured for a DataNode, the DataNode stops providing services by default if one of the volumes is damaged.

You can change the value of dfs.datanode.failed.volumes.tolerated on MRS to specify the number of damaged disk volumes that are allowed. The DataNode can work properly as long as the specified number is not reached.

Procedure

1. Log in to FusionInsight Manager.

   For details about how to log in to FusionInsight Manager, see Accessing MRS Manager.

2. Choose Cluster > Services > HDFS > Configurations > All Configurations.
3. Search for the following parameters and change their values as required.

   Table 1 Parameters

   Parameter	Description	Example Value
   dfs.datanode.failed.volumes.tolerated	Number of damaged volumes that are allowed before the DataNode stops providing services. By default, there must be at least one valid volume. Value range: -1 to Number of disk volumes configured on the DataNode The value -1 indicates that the minimum number of valid volumes is 1. A value greater than or equal to 0 indicates the number of damaged volumes that are allowed.	-1

4. Save the settings. Restart the expired service or instance for the configuration to take effect.