This service-level alert is triggered if the number of corrupt or missing blocks
exceeds the configured critical threshold. This alert uses the
check_hdfs_blocks plug-in.
Some DataNodes are down and the replicas that are missing blocks are only on those DataNodes
The corrupt/missing blocks are from files with a replication factor of 1. New replicas cannot be created because the only replica of the block is missing
For critical data, use a replication factor of 3
Bring up the failed DataNodes with missing or corrupt blocks.
Identify the files associated with the missing or corrupt blocks by running the Hadoop
fsckcommandDelete the corrupt files and recover them from backup, if it exists
