Install Guide

Support for guest VMs with SAS pass-through disks
38 Dell EMC SC Series Storage with SAS Front-end Support for Microsoft Hyper-V | 3026-CD-WS | V3
5 Support for guest VMs with SAS pass-through disks
Use of pass-through (PT) disks is a legacy Hyper-V configuration that (while still supported) is discouraged by
Microsoft and Dell EMC. If a guest VM has the MPIO feature installed, it is necessary to change the
AllowFullSCSICommandSet attribute from “false” to “true” in order for a guest VM to support SAS volumes
that are presented as PT disks. This step is not required if the guest VM does not have the MPIO feature
installed.
Guest VM with MPIO installed
Modifying the AllowFullSCSICommandSet attribute can be done with PowerShell.
Note: The creation of guest VM clusters that utilize SAS PT disks as cluster disks is not supported.
5.1 Windows Server 2008 R2 and 2012
For MPIO-enabled guest VMs running on Windows Server 2008 R2 or 2012, complete the following steps for
each guest VM, substituting the name of the VM for Vm_Name. For guest VMs running on Windows Server
2012 R2 and newer, see section 5.2.
1. From the server that owns the VM, launch PowerShell with elevated (administrator) privileges, and
run the following commands:
$HyperVGuestName = "Vm_Name";
$VMManagementService = gwmi -Class "Msvm_VirtualSystemManagementService" -
Namespace "root\virtualization"
$Vm = gwmi -Namespace "root\virtualization" -Query "Select * from
Msvm_ComputerSystem Where ElementName = '$HyperVGuestName'"
$SettingData = gwmi -Namespace "root\virtualization" -Query "Associators
of {$Vm} Where ResultClass=Msvm_VirtualSystemGlobalSettingData
AssocClass=Msvm_ElementSettingData"
$SettingData.AllowFullSCSICommandSet = $true
$VMManagementService.ModifyVirtualSystem($Vm, $SettingData.GetText(1))
2. Reboot the VM.
3. Present one or more SAS pass-through disks to the guest VM.
4. Repeat steps 2–3 for additional VMs.