Not able to create folder inside C:\ClusterStorage

I ran this command as admin also but giving same error every time 

PS C:\WINDOWS\system32> mkdir C:\ClusterStorage\Volume1
mkdir : Access to the path 'Volume1' is denied.
At line:1 char:1
+ mkdir C:\ClusterStorage\Volume1
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : PermissionDenied: (C:\ClusterStorage\Volume1:String) [New-Item], UnauthorizedAccessExcep
   tion
    + FullyQualifiedErrorId : CreateDirectoryUnauthorizedAccessError,Microsoft.PowerShell.Commands.NewItemCommand