@raouia
"Host Disk Usage alert" Is actually a "Host-Level" alert is triggered if the amount of "disk space used on a host" (Not on DFS) goes above specific thresholds (50% WARNING, 80% CRITICAL default values ).
"fields.png" --> Shows the HDFS Usage. (Only the HDFS file system usage , Not the Disk Usage). This image shows that total 3GB of overall HDFS are being utilized so far at the cluster level.
"hosts.png" --> Shows the "Disk Usage" of the "Highlighted" Host (which is 88.53% used with total capacity 19.62GB)
"alerts.png" --> This alert performs advanced disk checks under Linux. This will first attempt to check the HDP installation directories if they exist. If they do not exist, it will default to checking /
.
For more details please see [1], So if you see the complete alert message then you will find that it might be showing the complete message as following (Please check the path that it calculates at the end it might be "/usr/hdp" so it can be different from the hosts.png usage)
Example:
Capacity Used: [84.15%, 17.7 GB], Capacity Total: [21.1 GB], path=/usr/hdp
[1] https://github.com/apache/ambari/blob/release-2.5.2/ambari-server/src/main/resources/host_scripts/al...