VMM Cannot find the device or this device is not valid for a boot device.

This error occurs when you rollout a Generation 2.
Issue occurs because the Bootmgfw.efi file is set as the first startup device that the VM tries to start from, instead of the .vhdx file which contains the operating system.


To resolve this issue you must change the firstbootdevice in the template.
Open a Virtual Machine Manager Command Shell:

Get-SCVMTemplate -name “Windows 2012 VM Template” | Set-SCVMTemplate -FirstBootDevice “SCSI,0,0″

Change multiple GEN2 templates.

Get-SCVMTemplate | where-object {$_.FirstBootDevice -cnotcontains "SCSI,0,0" -and $_.Generation -eq "2"} | Set-SCVMTemplate -FirstBootDevice "SCSI,0,0"


Every 15 minutes this event logged on my SQL servers:

A Kerberos error message was received:
on logon session
Client Time:
Server Time:
Extended Error: 0xc0000035 KLIN(0)
Client Realm:
Client Name:
Server Realm:
Server Name:
Target Name:
Error Text:
Error Data is in record data.

Error 0x0000035 means that we have an issue with duplicate SPNs.

Find duplicate SPNs on the server where the event occure

Run cmd as administrator:

setspn -X

Found 1 group of duplicate SPNs.

Look for duplicate SPNs in the domain

Run cmd as administrator on the domaincontroller.
ldifde -f C:\SPNs.txt -t 3268 -d dc="DOMAIN",dc="COM" -l serviceprincipalname -r (serviceprincipalname=*) -p subtree

Delete duplicate SPN

setspn -D MSSQLSvc/sql1.example.com:1433 sql1

Get WWN Windows Server

Windows Fibre Channel Information Tool.
Tool for gathering configuration information on your Fibre Channel SAN based on the SNIA HBAAPI for management of Fibre Channel Host Bus Adapters and discovery of SAN resources.

Downlaod the MSI file FCINFO:
Download FCinfo

Install the MSI file on your system.
Open a command prompt typ “fcinfo ?” for the commands.

Expand disk Hyper-v 2012 R2

Online expanding of a VHDX is only possible with:
VHDX files that are attached to a SCSI controller.

Generation 1 VMs Boot always from a IDE Hard Drive.
Generation 2 VMs Boot always from a SCSI Virtual Hard Drive.

The following Windows guest operating systems are supported as generation 2 virtual machines:

  • Windows Server 2012 R2
  • Windows Server 2012
  • 64-bit versions of Windows 8.1
  • 64-bit versions of Windows 8

VEEAM Failed to flush change tracking data. Using full scan incremental run.

Changed block tracking information is no longer being read, causing entire disks to be read instead of just the changed blocks.
This is a very generic error, so it is quite difficult to say what has happened.

Hyper-v Solution:

Run “sc stop veeamfct” and “sc start veeamfct” on the Hyper-V hosts affected to restart the Veeam Change Tracking service, and then see if the errors are resolved afterwards.



When you run VEEAM V8, you must install patch 1. After this update the Flush change tracking data errors are gone.
This patch can be downloaded from the here:

General access denied error (0x80070005)

This issue occurs when the VM Security permissions on the VHDx are gone. Every VM has a unique ID. This unique ID is added to the VHDx security permissions for accessing / locking files.
There are 2 possible solutions to fix this.

Solution 1:

Detach the VHDx with the “remove” remove button in Hyper-v or Failover cluster manager. Just make sure you don’t remove the actual file!

Attach the VHDx again.
Now you can start the VM.

Solution 2:
  1. In this example is the virtual machine ID 684B169F-DB4A-493F-B34A-762E205AB1E4
  2. Go to the node wich host this VM
  3. Open an elevated command prompt
  4. icacls <path of vhd> /grant "NT VIRTUAL MACHINE\<Virtual machine ID>":(F)
  5. Start the virtual machine