Known Issues in HDFS

Learn about the known issues in HDFS, the impact or changes to the functionality, and the workaround.

CDPD-28459: After performing an upgrade rollback from CDP 7.1.7 to CDH6, you may see the following error when restarting the DataNodes: ERROR datanode.DataNode: Exception in secureMain java.io.IOException: The path component: '/var/run/hdfs-sockets' in '/var/run/hdfs-sockets/dn' has permissions 0755 uid 39998 and gid 1006. It is not protected because it is owned by a user who is not root and not the effective user: '0'.
You must run the command described in the error message "chown root /var/run/hdfs-sockets". After this, the DataNode will restart successfully.
CDPD-28390: Rolling restart of the HDFS JournalNodes may time out on Ubuntu20.
If the restart operation times out, you can manually stop and restart the Name Node and Journal Node services one by one.
OPSAPS-60832: When decommission of DN runs for a longer time and when decommission monitor's kerberos ticket expires, it is not auto-renewed. Decommission of DN is not completed in CM as decommission monitor fails to fetch the state of DN after kerberos ticket expiry.
Decommission state of DN can be fetched using CLI command, i.e, hdfs dfsadmin -report.
Unsupported Features
The following HDFS features are currently not supported in Cloudera Data Platform: