function Get-VMDiskInformation {
    <#
    .SYNOPSIS
    Returns information about the VMWare volumes and associated
    Windows drives on a given guest.

    .DESCRIPTION
    Function connects to vSphere and a given Windows guest and
    returns the Windows phyical disk information mapped to the
    disks in VCenter.

    .PARAMETER VSphereServer
    FQDN of vSphereServer that hosts the VM

    .PARAMETER ComputerFQDN
    FQDN of the target server

    .PARAMETER Credentials
    An option parameter to take a credential object in. This
    is then used to authenticate with VSphere
    #>
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory=$True)][ValidateNotNullOrEmpty()]
        [string]$VSphereServer,
        [Parameter(Mandatory=$True)][ValidateNotNullOrEmpty()]
        [string]$ComputerFQDN,
        $Credentials
    )

    Import-Module VMware.VimAutomation.Core

    # get user credentials to connect to vSphere
    if ( -not $Credentials ) {
        $Credentials = $(Get-Credential)
    }
    
    # initialise arrays
    $g_mounts = @()
    $results = @()

    # set error action
    $ErrorActionPreference = "Stop"

    # connecting to vSphere
    $Start = Get-Date
    Write-Host "Connection to VSphere Server..."
    $vSphere = Get-VIServer -Server $VSphereServer -Credential $Credentials -Force

    # retrieving VM object
    Write-Host "Getting VM Object..."
    $VMName =   Get-View -Viewtype VirtualMachine -Property guest.hostname, name `
                | Where-Object { $_.guest.hostname -eq $ComputerFQDN } `
                | Select-Object -ExpandProperty Name
    $VM = Get-VM -Server $vSphere.Name -Name $VMName

    Write-Host "Getting Disks..."
    # getting disk information
    $v_disks = $VM | Get-HardDisk | Sort-Object -Property Id
    $Session = New-CimSession -ComputerName $ComputerFQDN

    # Some servers return duplicate entries when grabbing the physical disks,
    # so we first grab the in-use serial numbers to filter the physical disks
    $g_disk_serials = Get-Disk -CimSession $Session | Select-Object -ExpandProperty SerialNumber

    # get physical disk info, but only for disks with serial numbers that appear
    # in `Get-Disk`. We NEED the physical location to properly map the drives.
    $g_disks = Get-PhysicalDisk -CimSession $Session `
                | Where-Object { $_.SerialNumber -in $g_disk_serials } `
                | Select-Object -Property PhysicalLocation,DeviceID,SerialNumber -Unique `
                | Sort-Object -Property PhysicalLocation,DeviceID

    Write-Verbose "Disk Info:"
    Write-Verbose " - VMWare Disks: $($v_disks.Count)"
    $v_disks | ForEach-Object {
        Write-Verbose "  - $($_)"
    }
    Write-Verbose " - Guest Disks: $($g_disks.Count)"
    $g_disks | ForEach-Object {
        Write-Verbose "  - $($_)"
    }

    Write-Host "Finding mount points..."
    # adding disk information to g_mounts array, ignore empty mount paths
    $CimPartInfo =  Get-Partition -CimSession $Session `
                    | Where-Object { $_.AccessPaths } `
                    | Select-Object -Property DiskNumber,AccessPaths,PartitionNumber
    foreach ($CimPart in ($CimPartInfo | Where-Object { $_.AccessPaths } )) {
        $g_mounts += [PSCustomObject]@{
            Path = $CimPart.AccessPaths[0]
            DiskNumber = $CimPart.DiskNumber
            PartitionNumber = $CimPart.PartitionNumber
        }
    }
    Write-Verbose "Mount Point Info:"
    $g_mounts | ForEach-Object {
        Write-Verbose " - ID: $($_.DiskNumber) - $($_.Path)"
    }

    # map the vm disks to the guest disks (include mount points if used)
    for($i=0;$i -lt $v_disks.Count;$i++){
        $v_disk = $v_disks[$i]
        $g_disk = $g_disks[$i]
        $g_mount = $g_mounts | Where-Object { $_.DiskNumber -eq $g_disk.DeviceId -and $_.Path }

        # adding disk information to results array
        if ( $g_drives -notcontains 900 ) {
            $results += [PSCustomObject]@{
                # In cases where a disk has multiple partitions and multiple mount points
                # we only care about reporting the disk number once.
                DiskNumber = $g_mount.DiskNumber | Select -First 1
                PartitionNumber = $g_mount.PartitionNumber
                VMWareDisk = $v_disk.Name
                DiskSerial = $g_disk.SerialNumber
                Path = $g_mount.Path
                CapacityGB = $v_disk.CapacityGB
            }
        }
    }

    # return results array
    $results
}