Get-WmiObject -Class win32_volume

we are using powershell script for capturing the disk space & memory utilization related parameters for x number of servers and using the command "Get-WmiObject -Class win32_volume" we are able to get the required output for most of the servers , however couple of servers are throwing the following two type of errors :

1. Get-WmiObject : Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

2. Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

In the above error # 1, its being observed that the servers which are in DMZ/ not in Windows Domain are throwing this error, however ,

the error # 2 above is for set of servers which are in Non-DMZ and placed inside Windows Domain and still throwing the error.

The option of using the "Get-WmiObject win32_service –credential mydomain\administrator" is not helping as the server count is huge.

Seems, some workaround can be explored using the option of "Enter -PSSession"

Kindly help in above scenario at the earliest.