How to fix duplicated MACs on Hyper-V hosts


Days ago a costumer reported that saw duplicated MACs in all hosts of a Hyper-V Failover cluster.


And Powershell showed that was true, in both teamings (Look on VM and MGMT) in every host we saw duplicated MAC.


The solution was force MAC Address in both teamings with a new MAC.

To do that, I went to Device Manager and I added 90-E2-BA-7B-DD-A7 and 98-BE-94-2B-92-C6 for my case in that host (Of course on the others Hyper-V hosts I did the same but with different MACs).


Remark that Hyper-V and SCVMM use different MAC Address scopes and doesn’t overlap.



Installing Legacy Network driver in WS 2003 VM over Hyper-V


When you want install a Win 2003 Server over Hyper-V (win 10) and you see that network card doesn’t works, you need to remove the network card, add a Legacy network card and after use the Windows 7 drivers.

To do that go to Windows 7 machine, find C:\Windows\System32\DriverStore\FileRepository and copy the folder dc21x4vm.inf_amd64_neutral_8887242a56ee027e or the same but with differents hexadecimal numbers.

Once done, make an iso with this folder and connect it to your virtual machine Windows 2003 and use this driver.


Strategy to manage Baselines to your Fabric Infrastructure

Hello folks,

With the following workflow we can see an entire upgrade cycle of a baseline. With this, when is the second Wednesday of every month we will upgrade PRE to check if all updates applied to Hyper-V works fine. To start with this we synchronize SCVMM for download all new updates from Update Server and we will notify managers that we will upgrade all Hosts groups for PRE. Done that we will analyze what updates are necessary for our hosts and we will add to the Baseline. Next week we start to upgrade one single host, member of a cluster, in a Hosts Group starting a Maintenance Mode and Scanning and Remediating it. If some update or the hyper-v host has a problem we will check which the cause is and we will solve it. If it finish fine we do the same for the others hyper-v hosts in the same cluster, if it´s ok then we do a maintenance mode and a scan and remediate for every one of all hosts groups for PRE. When we finish for all hosts groups in PRE and all is ok we will start with PRO in the next week. If some update or host has a problem we will check which the cause is and we will solve it.

I’m sorry, I have wrote this design in spanish.

Workflow de Baselines 0.1


Where to check hardware compatibility list with Hyper-V OS versions


When I do a desing of a Hyper-V environment, I used to check the hardware compatibility of the servers, SAN and connectivity the website although it’s good check also the vendor website.

With this and MAP Toolkit I can do a realistic design of a future Hyper-V environment.


Make an OS template from wim image for WS 2012 R2

Hi guys!

Here I writte how to make a vhdx when you have built an image with DISM for WS 2012 R2 Standard.


WADK 8.1

WS 2012 R2 CU1.


Creating vhdx disk:

• Diskpart

o create vdisk file=E:\temp\golden.vhdx maximum=122880 type=expandable
o select vdisk file=E:\temp\Image\golden.vhdx
o Attach vdisk
o Create partition primary size=350
o Format quick fs=ntfs
o Assign letter=s
o Active
o Create partition primary
o Format quick fs=ntfs
o assign letter=V
o Exit

Applying wim image to vhdx with dism:
• dism /apply-image /imagefile: E:\temp\ISO_2012R2\sources\golden.wim /index:2 /applydir:V:\

Type the following command to specify that V is the drive for Windows Boot Manager and the boot configuration data:
V:\windows\system32\bcdboot V:\windows /s S: (S: is the recovery partition)

Use the bcdedit /store <path> option to specify the BCD file inside the VHD as the BCD store, for example:

• bcdedit v:\windows

Bcdedit /store s:\Boot\bcd /set {bootmgr} device locate (where s: is the recovery partition)
Bcdedit /store s:\Boot\bcd /set {default} device locate (where s: is the recovery partition)
Bcdedit /store s:\Boot\bcd /set {default} osdevice locate (where s: is the recovery partition)

• Diskpart
o Select vdisk file= E:\temp\ISO_2012R2\sources\golden.vhdx
o Detach vdisk
o Exit

I hope it will be helpfull


Script to check updates for Hyper-V hosts and Hyper-V FC


Hans Vredevoort make a PS script that check if your Hyper-V 2012 or 2012 R2 is up to date and also your Hyper-V Failover cluster.

Here I put the link to his blog to see how to do and from where download the scripts.


Regional settings overrided to en-US when using a vm template from SCVMM 2012

Hi guys,

These days I´m deploying VM from vm templates. We found that when you deploy a new vm from a VM Template the regional settings are configured en-US, overriding other settings.

I found an article that fix this issue and in my case the I only have needed the following:

$template = Get-SCVMtemplate | where {$_.Name -eq “Template_Name”}
$settings = $template.UnattendSettings;


Set-SCVMTemplate -VMTemplate $template -UnattendSettings $settings

You can check the regional settings for all vmtemplates with the following PS1 sintaxis (change 2vNICs by other equal in all vmtemplates):

Get-SCVMtemplate | where {$_.Name  -like “*2vNICs*”}  | fl name,unattendsettings