:original_name: mrs_01_1690.html

.. _mrs_01_1690:

FAQ
===

-  :ref:`NameNode Startup Is Slow <mrs_01_1691>`
-  :ref:`Why MapReduce Tasks Fails in the Environment with Multiple NameServices? <mrs_01_1692>`
-  :ref:`DataNode Is Normal but Cannot Report Data Blocks <mrs_01_1693>`
-  :ref:`HDFS WebUI Cannot Properly Update Information About Damaged Data <mrs_01_1694>`
-  :ref:`Why Does the Distcp Command Fail in the Secure Cluster, Causing an Exception? <mrs_01_1695>`
-  :ref:`Why Does DataNode Fail to Start When the Number of Disks Specified by dfs.datanode.data.dir Equals dfs.datanode.failed.volumes.tolerated? <mrs_01_1696>`
-  :ref:`Why Does an Error Occur During DataNode Capacity Calculation When Multiple data.dir Are Configured in a Partition? <mrs_01_1697>`
-  :ref:`Standby NameNode Fails to Be Restarted When the System Is Powered off During Metadata (Namespace) Storage <mrs_01_1698>`
-  :ref:`Why Data in the Buffer Is Lost If a Power Outage Occurs During Storage of Small Files <mrs_01_1699>`
-  :ref:`Why Does Array Border-crossing Occur During FileInputFormat Split? <mrs_01_1700>`
-  :ref:`Why Is the Storage Type of File Copies DISK When the Tiered Storage Policy Is LAZY_PERSIST? <mrs_01_1701>`
-  :ref:`The HDFS Client Is Unresponsive When the NameNode Is Overloaded for a Long Time <mrs_01_1702>`
-  :ref:`Can I Delete or Modify the Data Storage Directory in DataNode? <mrs_01_1703>`
-  :ref:`Blocks Miss on the NameNode UI After the Successful Rollback <mrs_01_1704>`
-  :ref:`Why Is "java.net.SocketException: No buffer space available" Reported When Data Is Written to HDFS <mrs_01_1705>`
-  :ref:`Why are There Two Standby NameNodes After the active NameNode Is Restarted? <mrs_01_1706>`
-  :ref:`When Does a Balance Process in HDFS, Shut Down and Fail to be Executed Again? <mrs_01_1707>`
-  :ref:`"This page can't be displayed" Is Displayed When Internet Explorer Fails to Access the Native HDFS UI <mrs_01_1708>`
-  :ref:`NameNode Fails to Be Restarted Due to EditLog Discontinuity <mrs_01_1709>`

.. toctree::
   :maxdepth: 1
   :hidden: 

   namenode_startup_is_slow
   why_mapreduce_tasks_fails_in_the_environment_with_multiple_nameservices
   datanode_is_normal_but_cannot_report_data_blocks
   hdfs_webui_cannot_properly_update_information_about_damaged_data
   why_does_the_distcp_command_fail_in_the_secure_cluster_causing_an_exception
   why_does_datanode_fail_to_start_when_the_number_of_disks_specified_by_dfs.datanode.data.dir_equals_dfs.datanode.failed.volumes.tolerated
   why_does_an_error_occur_during_datanode_capacity_calculation_when_multiple_data.dir_are_configured_in_a_partition
   standby_namenode_fails_to_be_restarted_when_the_system_is_powered_off_during_metadata_namespace_storage
   why_data_in_the_buffer_is_lost_if_a_power_outage_occurs_during_storage_of_small_files
   why_does_array_border-crossing_occur_during_fileinputformat_split
   why_is_the_storage_type_of_file_copies_disk_when_the_tiered_storage_policy_is_lazy_persist
   the_hdfs_client_is_unresponsive_when_the_namenode_is_overloaded_for_a_long_time
   can_i_delete_or_modify_the_data_storage_directory_in_datanode
   blocks_miss_on_the_namenode_ui_after_the_successful_rollback
   why_is_java.net.socketexception_no_buffer_space_available_reported_when_data_is_written_to_hdfs
   why_are_there_two_standby_namenodes_after_the_active_namenode_is_restarted
   when_does_a_balance_process_in_hdfs_shut_down_and_fail_to_be_executed_again
   this_page_cant_be_displayed_is_displayed_when_internet_explorer_fails_to_access_the_native_hdfs_ui
   namenode_fails_to_be_restarted_due_to_editlog_discontinuity