virtual machine disk usage is higher than the provisioned space in vCenter

Products

• VMware vCenter Server

Issue/Introduction

• The output of the power cli to obtain disk usage of virtual machine shows the below response

                   get-vm V_name|select-Object -Property Name,guest,ProvisionedSpaceGB,@{N='UsedSpaceGB';E={($_.Guest.Disks | Measure-Object -Property CapacityGB -Sum).Sum - ($_.Guest.Disks | Measure-Object -Property FreeSpaceGB -Sum).Sum}} | ft -a

                     Name             Guest           ProvisionedSpaceGB                        UsedSpaceGB
                     ----             -----           ------------------                       -----------
                   vm_name    vm_name:os_version  Disk usage as seen in Vcenter     Disk usage showing higher than the one is Vcenter    

• Reports from Aria operations for the virtual machine will show guest OS usage higher than provisioned space

Environment

VMware vCenter 

Cause

This behavior occurs because storage such as NFS is presented directly to the virtual machine.

Resolution

Check the virtual machine for any directly presented storage, such as NFS mounts, that would impact the guest OS usage.