Dedicated host with nothing placed on it
A dedicated host billing its full hourly rate with no virtual machine assigned to it.
Why it happens
A dedicated host bills for existing, at the same rate whether it carries a full complement of machines or none at all, and the rates are the largest single figures in this catalogue: measured live in East US, host SKUs run from about $3.37 to $14.67 an hour, which is roughly $2,460 to $10,700 a month each. A host left behind after a migration, or provisioned ahead of a project that went elsewhere, bills all of that for nothing. Emptiness is established by joining rather than by reading a property, because the dedicated host resource carries no list of the machines on it: Azure records the relationship on the MACHINE, at properties.host.id, so the rule matches every virtual machine against every host. That has a consequence worth stating plainly on every finding: if virtual machines were not collected, every host would look empty, so the rule reports nothing at all rather than risk the most expensive false positive it could produce. The saving is the host meter at the hourly rate for its SKU, and where that SKU is not sold in the region the host is reported with no figure rather than a guessed one, because an empty host is waste whether or not its meter is still published.
What the agent does about it
A dedicated host billing its full hourly rate with no virtual machine assigned to it.
It will not fix this one
It reports this and takes no action. A check only earns the right to change something once the action behind it can re-read live state before it fires and knows the way back.
Related checks
Idle virtual machine
A running VM whose CPU and network have been near zero for the whole window.
Oversized virtual machine
A running VM whose sustained peak fits comfortably inside the next size down.
Unattached managed disk
A managed disk attached to nothing, billing its full provisioned size every month.