Jason Yoder, MCT

In Hyper-V R1, we had the option to export out a VM and then later import it back in again.  For many in testing environments, this created large export files when only the VM with a specific snapshot was needed.  With Hyper-V R2 we can now create a new VM from a snapshot of another one.  This is advantageous because now you can create an entire new VM without all the extra files from other snapshots that you may not want.  Take a look at my screen shot below of my snapshot tree. Let’s say that I want to create a new VM from this one. Apply the snapshot that you want to use as the base for the new VM. Right click the VM and select Export.  Give it a location and click Export . One thing that I do not like about this process is that you will not see any progress bars or other indicators to let you know when the export is finished.  Your VMs will not be able to start until the export is completed.  If you look in the destination that you specified, ...

Until now, you were not able to over allocate RAM to virtual machines running Hyper-V.  You could allocate enough static RAM to a set of VMs that would exceed the total amount of RAM on the server, but you would not be able to start all your virtual machines. Part of server consolidation is the ability to take servers that are underutilized and move their operations to a single server.  This has worked well however, even when a virtual machine was not taxed to its maximum memory load, it still consumed the same amount of memory and therefor was a hindrance to further consolidation. Dynamic memory allows you to safely increase the VM density on a server.  This feature requires Windows Server 2008 R2 SP1 and is available on the following guest partitions: Windows Server 2003 Enterprise and Datacenter with SP2 (32 and 64-bit versions) Windows Server 2003 R2 Enterprise and Datacenter with SP2 (32 and 64-bit versions) Windows Server 2008 Enterprise and Datacenter (32 an...

The idea behind a VLAN is isolation.  On the same Hyper-V Server, the two clients in question would have to connected to the same virtual network to communicate.  This defeats the purpose of this question.  I set up two different VMs on 2 different Hyper-V Servers.  Both were placed on external Virtual Networks and were able to PING each other.  On one of the virtual networks, I enabled VLAN with an ID of 2.  I also enabled it in the settings of the VM.  Once this change took effect, the two VMs lost communication with each other. In conclusion, the VLAN also isolates, as it should, communication between clients for both the virtual and physical worlds.  Therefore, no RDP traffic can pass between them.

There seems to be a bit of a debate on the internet about this one.  I executed the following PowerShell command on 2 different computers: Get-WMIObject Win32_ComputerSystem | FL *   I executed it on a laptop with 1 physical processor with 4 logical processors and received the following results:     I then executed it again on a desktop with 1 physical processor and 8 logical processors:     From my testing, the NumberOfProcessors property seems to provide the correct number of physical processors.   I got curios and ran that PowerShell code on a virtual machine with 1 assigned processor:     I also ran it on a virtual machine with 4 processors assigned to it:     OK, so how do you know if you are looking at a virtual machine or a physical machine?  A couple of properties higher in the list you will see Model .  If this was a virtual machine, it would say Virtual Machine . ...

Below is a list from a Microsoft article : VMware Support   VMM 2008 and VMM 2008 R2 support VMware VirtualCenter 2.5 (VMware Infrastructure 3 [VI3]), with the following versions of VMware ESX Server: VMware ESX Server 3.5 VMware ESX Server 3.0 or above   VMM 2008 R2 also supports VMware vSphere 4 (VI3 features only), with the following versions of ESX Server: VMware ESX Server 4.0 ESX Server 3.5 ESX Server 3.0 or above   VMM does not support VMware Server.

Yes it does.  In class we talked about enlightened, and non-enlighten guests partitions.  When you install the integration services, you allow for Microsoft’s support for paravirtualization.  Paravirtualization is called “enlightened” in Microsoft’s documentation. This reduces the emulation of physical components, such as the network interface, and provides a performance improvement and additional system management options. Integration services are built into Vista SP1 and later operating systems. Below is a list of operating systems that Hyper-V can provide integration services for: •Microsoft Windows Server 2003 (all versions) •Microsoft Windows 2000 Server •Microsoft Windows NT Server 4.0 with Service Pack 6a (SP6a) •Microsoft Windows XP (all versions) •Microsoft Windows 2000 Professional •Microsoft Windows Millennium Edition •Microsoft Windows 98 •Microsoft Windows 95

In class I miss quoted Microsoft.  In Microsoft’s’ documentation, the actual wording is “the initial size of the .vhd file is only about 3 MB.”  So I created 4 dynamically expanding VHD files.  Their maximum sizes are 1GB, 10GB, 100GB, and 2TB.  Below is a screen shot of their initial sizes:

According to Microsoft , Windows Server 2008 R2 can support up to 256 logical processors.  Just to get a visualization, I found an image of task manager with this configuration. Here is the next question.  What application can cause such a high processor utilization?

Windows Management Instrumentation (WMI) is the cornerstone behind successful PowerShell and SCVMM management.  This was a good question and generated quit a list.  The below PowerShell command needs to be executed on a Windows Server 2008 client with the Hyper-V role installed. Gwmi –namespace root\virtualization –list | Where {$_.Name –like “*msvm*”}

The answer to this one is mixed.  Microsoft states the NTFS has not been adopted to this technology and produces and error in the difference between the physical and virtual capacities of your Pass Through disks.  Microsoft provides some guidance to help you utilize Thin Provisioning in your environments.  Refer to this link to view the article.

Microsoft officially supports many of its own Operating Systems from the past, as well as some third party Operating Systems, in Hyper-V.  For a complete list from Microsoft, click here .  From time to time, I have a student in class that still needs to support Windows NT 4.0.  NT4 is not on the list of supported guest operating system for Hyper-V.  You can get it to work though.  When you create the VM in Hyper-V, open its Settings . Click Processor . Notice at the bottom the setting for Run an older operating system, such as Windows NT . Even with this option enabled, Windows NT4 is not supported by Microsoft in a Hyper-V environment.  You need to thoroughly test your implementation to make sure the results are acceptable.

Pass Through disks are ideal in situations in which you need to exceed the 2 TB capacity limitation of the .VHD format.  In using a Pass Through disk, you will not have the ability to use snapshots.  The maximum size for a Pass Thru disk is????  Unfortunately after a long Google and Bing session, I could not find this answer.  I did find an article about an organization that linked (6) 2 TB hard drives and created a 12 TB pass-through disk that was functional.  I also saw that during some maintenance, they had a problem getting the VM back online. As always, test before putting a new configuration into production. Please post your maximum Pass Through disks sizes here and tell us how successful your implementation has been.

If you recently made a change to the Boot Configuration Data store, you may see this error when starting a VM in Hyper-V First, verify that virtualization support is turned on in your BIOS.  If it is and a power cycle of the server does not resolve the problem, you may not have the Hypervisor loading during the boot sequence.  To check for this problem, open a command prompt with administrative privileges. Type bcdedit and press Enter .  Tyhe output in red is the currently loaded boot configuration The output in blue is a boot configuration that will allow Hyper-V to run. Notice the data in green is missing from the current boot configuration. Type bcdedit /set {current} hypervisorlaunchtype auto and press Enter .  You should get a response The operation completed successfully . Type bcdedit to see the new results. Now, restart the server and give it a try.

Virtualizing your servers is a good way to reduce your expenses through hardware reduction.  You simply take several underutilized servers and move their activities to a single server.  This does create the obvious issue of single point of failure. This set of instructions will help you set up a test lab for Hyper-V failover.  In a production failover environment, you would utilize at least 2 servers for the fail over cluster.  It is best to use two identical servers for this purpose. Also, you need to check to make sure all the hardware in the servers is supported by Windows Server 2008 R2.  It increases the chances of a successful failover.  You should also have 2 NICs in these servers.  One for the public network, and one for the storage network.  The final element will be a highly available storage system.  This storage system will hold the virtual machine.  A simple diagram of this setup looks like this: In this test, we will u...

It never fails.  I need to start up a new VM only to find out that I do not have enough RAM (see the error below). From the last line of the error, you can see “Fail to create partition: Insufficient resources exist to complete the requested service.”   Ok, but I really need to start this VM.  We cannot dynamically change the amount of RAM that is allocated to a VM while it is running.  One option that we have is to take a VM that is in a Paused state, and change it to a saved state.  Since the VM was already paused, you were not using its functionality anyway.  Right click the paused VM and click Save If this cleared up enough resources, you can now start that other VM. Should I need to run both VMs, I will still need to shut the paused virtual machine down and reallocate less resources from it while it is offline.

In any medium to large network environment, there are undoubtedly certain servers that need to be fully online before others.  Generally the IT staff would have some type of restart procedure that will bring these servers back up in the correct order should they ever go down for some reason.  When working with virtualized machines, you still have this same capability using Hyper-V. To configure a startup delay, open the Hyper-V Manager . Right click the VM that you want to configure the delay on and click Settings . Click on Automatic Start Action . You need to select Automatically start if it was running when the service stopped or Always start this virtual machine automatically You than need to specify the number of seconds until the VM starts. You may have to take some time with a stop watch to get an idea of how long to make the delay.