Error: Get-ScsiLun Value cannot be null. Any clues

Hi,

I would like to retrieve Canonical Name and CapacityMB.

PowerCLI C:\Program Files (x86)\VMware\Infrastructure\vSphere PowerCLI> $vmHost = Get-VMHost -Name ESXiServer.Domain.Com

PowerCLI C:\Program Files (x86)\VMware\Infrastructure\vSphere PowerCLI> Get-ScsiLun -vmHost $vmHost -LunType "disk"

Get-ScsiLun : 9/11/2013 10:56:47 AM    Get-ScsiLun        Value cannot be null.

Parameter name: array

At line:1 char:12

+ Get-ScsiLun <<<<  -vmHost $vmHost -LunType "disk"

    + CategoryInfo          : NotSpecified: (:) [Get-ScsiLun], VimException

    + FullyQualifiedErrorId : Core_BaseCmdlet_UnknownError,VMware.VimAutomatio

   n.ViCore.Cmdlets.Commands.Host.GetScsiLun

Get-ScsiLun : 9/11/2013 10:56:48 AM    Get-ScsiLun        ScsiLun with luntype

'disk' was not found using the specified filter(s).

At line:1 char:12

+ Get-ScsiLun <<<<  -vmHost $vmHost -LunType "disk"

    + CategoryInfo          : ObjectNotFound: (:) [Get-ScsiLun], VimException

    + FullyQualifiedErrorId : Core_OutputHelper_WriteNotFoundError,VMware.VimA

   utomation.ViCore.Cmdlets.Commands.Host.GetScsiLun

Any clues to get the canonicalName and CapacityMB

Thanks