Data Center Cost Driver History is different from Cost History

Products

• CloudHealth

Issue/Introduction

The reporting in Cost Driver History does not function the same way that Cost History does.  Cost Driver History is the cost of the underlying infrastructure, and Cost History is the cost of the VMs running on that infrastructure. 

Resolution

The difference between Cost Driver History and Cost History is due to the difference between total infrastructure and "used" infrastructure.  If the organization efficiently utilizes the infrastructure, by packing more VMs onto clusters, the monthly cost shown in Cost History should move closer towards Cost Driver History for that month.  Typically the monthly cost of sum of all VMs will be less than the sum of cost drivers, as there will usually be room to pack more VMs and there is slack space available in the underlying infrastructure.

A simplified example - The cost of an ESxi host = $1000, with 50 identical VMs deployed at 10$ each. Cost History will show $500, and Cost Driver History will show $1000.  If you deploy 50 more VMs, the Cost History and Cost Driver History will start matching, but this will be dynamic, based on how the workload deployed keeps changing over time.

Perspective support is also different in Cost Driver History.  The Cost Driver History report shows data at a cost driver level based on CAPEX spend amortized monthly.  It is not attributed to objects such as VMs and file systems and for this reason perspectives built with these objects do not work in this report.  The standard Cost History report has CAPEX distributed to VMs, which is why perspectives work.