Results for category "Windows Server 2012 HyperV"

A port on the virtual switch has the same MAC as one of the underlying team members on Team Nic

On my Windows 2012 R2 HyperV Cluster, The event 16945 was getting logged frequently.



The current setup has two network interfaces teamed and this teamed interface is used for creating the Virtual Switch.  The virtual switch, the teamed inteface and one of the team member are having the same MAC Address which is the base of this event.




In my observation, This event will go off if we unchecked the option “Allow management operating system to share this network adapter” from Virtual Switch Manager. By doing so will remove the virtual interface – vEthernet and have the  configuration directly on Virtual Switch.



Its recommended to have dedicated interfaces for Management, HyperV Data, LiveMigrationa and CSV. If you have a dedicated interface for Management, this you can go ahead with this option.



Windows 2012 R2 – New HyperV Feature – Live-Export

Trying out the new features with Windows 2012 R2. One of the interesting features is the Live Export. In the previous versions of HyperV, its mandatory to keep the VM down while performing an export.


With Windows 2012 R2, that restriction is lifted out.

The idea which is getting used here is similar of a snapshot. While we take a snapshot, a differencing disk is created from that point which will have the updates. This disk will have the extension .avhdx (Advanced Virtual Hard Disk). In case of a restore, This ahvdx is discarded and the parent disk will be used. At the time of deleting a snapshot, the avhdx will get merged to vhdx.

In Windows 2012 R2, While we perform a live export – a snapshot is happening in the background which creates a avhdx file. All the updates will be happening to this differencing disk till the export gets completed. Once the export is completed, this avhdx will get merged to the parent disk.

Lets see how it works.

I am going to export a VM named  VM1.

Please refer to the disk configuration of VM1. Now the VHDX configured is VM1.VHDX.


Triggering a live export from Powershell. Please note – We need to open the powershell on elevated mode.


While the export is in progress, Lets go back to the disk configuration and see the current disk.


Lets wait for the export process to complete. The progress will be visible on the HyperV Manager.


And once the export is done, We will see that merging in progress. At this stage, the avhdx disk which got created is getting mreged back to the parent vhdx – in this example, vm1.vhdx.

LiveExport-Export-VM-DiskMerging-After-Completion-Of-Export   Additionally, Few events are getting logged while the export is happening. Refer to the Crimson Logs Microsoft-Windows-Hyper-V-VMMS/Admin

Live-Export-Event18303-ExportCompleted Live-Export-Event19070-DiskMergeStarted Live-Export-Event19080-DiskMergeCompleted

For any questions/suggestions, Feel free to drop as a comment.




Network Virtualization with SCVMM 2012 Sp1 – Some key points before start

I was running around this topic for the last few months. Once we had Windows 2012 HyperV Clusters, the next target was to try out network virtualization. Unfortunately, SCVMM 2012 Sp1 was not ready at that time. Recently, we got that. We did attempted and few points which I understood now is

  • For enabling communication between a Network Virtualized subnet and a non network virtualized subnet, A Virtualization Gateway needs to be in the middle
  • Virtualization Gateway devices are still under development and major network vendors are getting ready for release
  • Microsoft is coming up with Software-based NV Gateway which will be fully integrated with SCVMM
  • F5 is also coming with Network Virtualization gateway – but time lines are not confirmed

To my knowledge, the whole stuff is amazing but its complicated. Lack of documentation and information makes it complicated and I expect to see more official documentation coming up for NV in the coming days.

If you have any further information to add on, Please comment. I am open for a discussion.



MPIO and Windows 2012 Server

I was trying to configure Multi-path software for a new cluster which is using Dell Compellent storage. Installed MPIO feature and was trying different options to get it configured. However, after each reboot, I still see two disk for each volume.

While trying to discover the Multipath from MPIO graphical interface, I noticed an error.

The program can’t start because MSVCR100.dll is missing from your computer


MPIO Error

If I click on OK, Configuration will continue and end up in a reboot prompt. After reboot, I will still see two disk for each volume.

At last, I got a write-up which gave me a clue that this is a generic error where VC++ redistributable is missing. So on the next node, I tried it and it was successful.

The first step before starting MPIO configuration was installaing Microsoft Visual C++ 2010 Redistributable Package (x64)

And then proceed with MPIO configuration. From MPIO control Panel, Select Discover Multi-Path and then select Compellent from the list of devices listed. After that, Click on Add. System will configure MPIO and may take few minutes to complete.


Configuring MPIO on Windows 2012 Server

Configuring MPIO on Windows 2012 Server

At the end of configurations, a reboot prompt will be displayed. To complete MPIO configuration, Proceed with a reboot.



Installing HyperV3 – Pre-Check

In the last six months, I did installed multiple HyperV clusters. One important issue which I faced in the initial days is outdated firmwares. This may not be specific to HyperV3, but this will become an issue once you enable HyperV3. I had issues while enabling HyperV role, sometimes while creating a cluster.

We are crossing 6+ months with Windows Server 2012. Most of the vendors has released the new firmwares for Windows Server 2012. I had issues where the specific driver was only available for Windows 2008 R2, where we cannot update it from a Windows 2012 OS. Installation will throw an error which says that incompatible OS.

Update Firmware

Update Firmware error

Its always better to check each components and get the latest firmware and drivers prior to the HyperV configurations. If Windows 2012 is supported, you can try using bootable ISO images if possible.

Another important aspect of firmware update is due to the support for latest features like SR-IOV and ODX. The hardware may be having this feature but until the firmwares are updated to the latest one, we may not be able to use this.



SCVMM 2012 Sp1 – Building a priviate cloud

I am very excited to let you all know that I am trying out a private cloud with SCVMM 2012 Sp1. Its almost three weeks I am playing around SCVMM 2012 Sp1. Still trying to understand the concepts and features. In the initial phase, I was in the assumption that configuration is something which I can do easily. Unfortunately, Fabric configuration made me into panic mode having sequence of issues. At-last, I landed safely by fixing all issues.

Another important note is on Roll-up 1. As you are aware, System Center 2012 Sp1 got a new Roll-up1 which got released on Jan 9th 2013. This rollup is intented to fix the below issues. I am yet to apply this roll-up, but scheduled for this weekend.


Virtual Machine Manager (KB2792925 – Console; KB2792926 – VMM Server)

Issue 1

When a logical unit number (LUN) is unmasked on an iSCSI array, the VMM service may crash.

Issue 2

When a node is put in maintenance mode, virtual machines in the cluster change to a status of “Unsupported Cluster Configuration.”

Issue 3

When an add-in that uses multiple DLL files is imported into the VMM console, the add-in is not imported. Additionally, you receive the following error message:

Add-in cannot be installed

Issue 4

When an add-in is imported into the VMM console on a server that is running Windows Server 2008 R2, the add-in is not imported.

Issue 5

When an add-in is imported into the VMM console, the console may crash.

Cheers !