Ask the Core Team : Hyper-V

Unable to select an attached VHD as a Shadow Copy Storage location

jeffhugh — Tue, 27 Oct 2009 19:27:09 GMT

You may notice that you cannot choose to store Shadow Copies on an attached VHD, and that when configuring Shadow Copy protection on an attached VHD, there are no other locations available to store the copies on, other than the protected VHD volume.

This behavior is by design. Illustrated below is the behavior you may see while working with attached VHDs and Shadow Copies. I’ll provide some additional information at the end of this post that will explain why this behavior is occurring.

To get into a configuration where we’ll see the behavior I’m describing:

We create our VHD in Fig.1

(Fig.1)

Remember the size of the destination volume for shadow copies must be at least 300mb before you can store a single shadow copy on the volume

(Fig.2)

Here, in Fig.2, I’m making it 350mb so that there wouldn’t be any concern about the volume being too small and thereby omitted from the list of possible locations.

Below in Fig.3, we’re going through the steps of initializing the new disk

(Fig.3)

Now, in Fig.4, we’re putting a simple volume on it

(Fig.4)

(Fig.5) Enabling Shadow Copies on the C:\ volume

In Fig.5 above, I’ve pulled up the properties of the C:\ in preparation to enable Volume Shadow Copies. You can see here, that Disk 3 (F:\) is present in the list of volumes that we can enable the feature on. F:\ is the attached VHD we created in Fig.2.

In Fig.6, let’s enable Shadow Copies on C:\ and then choose to put the copies on our F:\ drive…

(Fig.6)

Whoa… where’d the F:\ drive go?

As you can see from the list, the attached F: (VHD file) is not listed as a valid target for Shadow Copy Storage.

Also, while you can configure the attached VHD to be protected with Shadow Copies, you cannot store the Shadow Copies on any other volume but itself.

Why is this happening?

A virtual volume cannot be used as the target volume for the snapshot of another volume, and the volume can only hold shadow copies associated with its own snapshots. VSS will constrain the shadow copy storage area for attached VHDs to only allow the volume to host its own shadow copies. This behavior will ensure that the volume is self consistent, and therefore, maintain its portability. Portability is one of the bigger design goals behind the ability to create and mount VHDs under Windows 7 and 2008/R2. The end result of this behavior is that snapshots of the volume will travel with the volume as it is deployed and moved around your environment so there’s never a need to worry about a volume missing when it comes time to restore a previous version of a file.

For additional information, be sure to visit these links:

Frequently Asked Questions: Virtual Hard Disks in Windows 7

http://technet.microsoft.com/en-us/library/dd440865(WS.10).aspx#one

Understanding Virtual Hard Disks with Native Boot

http://technet.microsoft.com/en-us/library/dd799282(WS.10).aspx

Thanks for taking the time to read this. I hope it’s helped you understand one of the caveats that can be seen when using Native VHD support!

Sean Dwyer
Support Escalation Engineer
Microsoft Enterprise Platforms Support

Top Issues for Microsoft Support for Windows Server 2008 Hyper-V (Q4)

jeffhugh — Mon, 14 Sep 2009 14:52:42 GMT

It is time for the final installment of a year-long segment on the top issues in Hyper-V. It is appropriate since Windows Server 2008 R2 has finally released, and we can look forward to tracking\reporting any issues we may find in the new version of Hyper-V. As always, the issues are categorized below with the top issue(s) in each category listed with possible resolutions and additional comments as needed. I think you will notice that the issues for Q4 have not changed much from Q1\Q2\Q3. Hopefully, the more people read our updates, the fewer occurrences we will see for some of these and eventually they will disappear altogether (if you have been following this blog series, you will notice some already have). Additionally, we continue to highly recommend the installation of Windows Server 2008 Service Pack 2 on all servers running the Hyper-V Role.

Deployment\Planning

Issue #1

Customers looking for Hyper-V documentation.

Resolution: Information is provided on the Hyper-V TechNet Library which includes links to several Product Team blogs. Additionally, the Microsoft Virtualization site contains information that can be used to get a Hyper-V based solution up and running quickly.

Installation Issues

Issue #1

After the Hyper-V role is installed, a customer creates a virtual machine, but it fails to start with the following error:

The virtual machine could not be started because the hypervisor is not running

Cause: Hardware virtualization or DEP was disabled in the BIOS.

Resolution: Enable Hardware virtualization or DEP in the BIOS. In some cases, the server needs to be physically shutdown in order for the new BIOS settings to take effect.

Issue #2

A customer was experiencing an issue on a pre-release version of Hyper-V.

Resolution: Upgrade to the release version (KB950050) of Hyper-V.

Issue #3

After the latest updates off Windows Update are installed or KB950050 is installed, virtual machines fail to start with one of the following error messages:

An error occurred while attempting to chance the state of the virtual machine vmname .
‘ vmname ’ failed to initialize.
Failed to read or update VM configuration.

An error occurred while attempting to change the state of virtual machine vmname .
" VMName " failed to initialize
An attempt to read or update the virtual machine configuration failed.
" VMName " failed to read or update the virtual machine configuration: Unspecified error (0x80040005).

Cause: This issue occurs because virtual machine configurations that were created in the beta version of the Hyper-V are incompatible with later versions of the Hyper-V.

Resolution: Perform the steps documented in KB949222.

Virtual Devices or Drivers

Issue #1

Synthetic NIC was listed as an unknown device in device manager.

Cause: Integration Components needed to be installed.

Resolution: Install Integration Components (IC) package in the VM.

Issue #2

Corrupted virtual hard disk (VHD) file.

Cause: The most common cause was a power outage or the server wasn’t shutdown properly.

Resolution: Restore the VHD file from backup.

Issue #3

Stop 0x00000050 on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: This issue can occur if a Hyper-V virtual machine is configured with a SCSI controller but no disks are attached (driver issue - Storvsp.sys).

Resolution: Perform the steps documented in KB969266.

Issue #4

Stop 0x0000001A on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: Vid.sys

Resolution: Install hotfix KB957967 to address this issue.

Snapshots

Issue #1

Snapshots were deleted

Cause: The most common cause is that a customer deleted the .avhd files to reclaim disk space (not realizing that the .avhd files were the snapshots).

Resolution: Restore data from backup.

For more information on Snapshots, please refer to the Snapshot FAQ: http://technet.microsoft.com/en-us/library/dd560637.aspx.

Issue #2

Snapshots were lost

Cause: Parent VHD was expanded (not supported). If snapshots are associated with a virtual hard disk, the parent vhd file should never be expanded. This is documented in the Edit Disk wizard:

Resolution: Restore data from backup.

Issue #3

Snapshots fail to merge with error 0x80070070

Cause: Low disk space.

Resolution: Free disk space to allow the merge to complete or move the .VHD and .AVHD file(s) to a volume with sufficient disk space and manually merge the snapshots.

Integration Components

Issue #1

On Windows Server 2008, when you attempt to install the Integration Components in a Hyper-V virtual machine running Windows Vista Service Pack 2, the installation may fail with the following error:

An error has occurred: One of the update processes returned error code 1.

Cause: This issue occurs if the management operating system (parent partition) that has the Hyper-V role installed does not have Service Pack 2 installed. If you have a virtual machine that’s running Windows Vista Service Pack 2, you need to use the Vmguest.iso from Service Pack 2 to install the Integration Components.

Resolution: Perform the steps documented in KB974503.

Issue #2

Attempting to install the Integration Components on a Server 2003 virtual machine fails with the following error:

Unsupported Guest OS

An error has occurred: The specified program requires a newer version of Windows.

Cause: Service Pack 2 for Server 2003 wasn’t installed in the virtual machine.

Resolution: Install SP2 in the Server 2003 VM before installing the integration components.

Virtual machine State and Settings

Issue #1

You may experience one of the following issues on a Windows Server 2008 system with the Hyper-V role installed or Microsoft Hyper-V Server 2008:

When you attempt to create or start a virtual machine, you receive one of the following errors:

The requested operation cannot be performed on a file with a user-mapped section open. ( 0x800704C8 )
‘VMName’ Microsoft Synthetic Ethernet Port (Instance ID {7E0DA81A-A7B4-4DFD-869F-37002C36D816}): Failed to Power On with Error 'The specified network resource or device is no longer available.' (0x80070037).
The I/O operation has been aborted because of either a thread exit or an application request. (0x800703E3)

Virtual machines disappear from the Hyper-V Management Console.

Cause: This issue can be caused by antivirus software that is installed in the parent partition and the real-time scanning component is configured to monitor the Hyper-V virtual machine files.

Resolution: Perform the steps documented in KB961804.

Issue #2

Customer has multiple Hyper-V servers and virtual machines are getting duplicate MAC addresses.

Resolution: Configure the Hyper-V servers to use unique MAC address ranges by modifying the MinimumMacAddress and MaximumMacAddress registry values on each Hyper-V server. This issue is documented on TechNet: http://technet.microsoft.com/en-us/library/dd582198(WS.10).aspx. On Server 2008 R2, the MAC address ranges can be configured in the UI.

Issue #3

Virtual machines have a state of "Paused-Critical"

Cause: Lack of free disk space on the volume hosting the .vhd or .avhd files.

Resolution: Free up disk space on the volume hosting the .vhd or .avhd files.

High Availability (Failover Clustering)

Issue #1

Virtual machine settings that are changed on one node in a Failover Cluster are not present when the VM is moved to another node in the cluster.

Cause: The "Refresh virtual machine configuration" option was not used before attempting a failover.

Resolution: We have a KB article (KB 2000016) which discusses this issue for Windows 2008. On Windows 2008 R2, the experience has improved. If the virtual machine settings are modified within the Failover Cluster Management console, changes that are made to the VM will be saved to the Cluster (i.e. synchronized across all nodes in the cluster). If you make changes to the VM using the Hyper-V Manager Console, you must select the refresh virtual machine configuration option before the VM is moved to another node. This issue is documented in the Windows Server 2008 R2 help file. There is also a blog that discusses this.

Issue #2

How to configure Hyper-V on a Failover Cluster.

Resolution: A step-by-step guide is available which covers how to configure Hyper-V on a Failover Cluster.

Backup (Hyper-V VSS Writer)

Issue #1

You may experience one of the following symptoms if you try to backup a Hyper-V virtual machine:

· If you back up a Hyper-V virtual machine that has multiple volumes, the backup may fail. If you check the VMMS event log after the backup failure occurs, the following event is logged:

Log Name: Microsoft-Windows-Hyper-V-VMMS-Admin

Source: Microsoft-Windows-Hyper-V-VMMS

Event ID: 10104

Level: Error

Description:

Failed to revert to VSS snapshot on one or more virtual hard disks of the virtual machine '%1'. (Virtual machine ID %2)

· The Microsoft Hyper-V VSS Writer may enter an unstable state if a backup of the Hyper-V virtual machine fails. If you run the vssadmin list writers command, the Microsoft Hyper-V VSS Writer is not listed. To return the Microsoft Hyper-V VSS Writer to a stable state, the Hyper-V Virtual Machine Management service must be restarted.

Resolution: An update (KB959962) is available to address issues with backing up and restoring Hyper-V virtual machines.

Issue #2

How to backup virtual machines using Windows Server Backup

Resolution: Perform the steps documented in KB958662.

Virtual Network Manager

Issue #1

Virtual machines are unable to access the external network.

Cause: The virtual network was configured to use the wrong physical NIC.

Resolution: Configure the external network to use the correct NIC.

Issue #2

After the customer configured a virtual machine to use a VLAN ID, the virtual machine is unable to access the network.

Cause: The VLAN ID used by the virtual machine didn’t match the VLAD ID configured on the network switch.

Resolution: How to configure a virtual machine to use a VLAN is covered in the Hyper-V Planning and Deployment guide.

Issue #3

How to configure a virtual machine to use a VLAN.

Resolution: How to configure a virtual machine to use a VLAN is covered in the Hyper-V Planning and Deployment guide.

Hyper-V Management Console

Issue #1

How to manage Hyper-V remotely.

Resolution: The steps to configure remote administration of Hyper-V are covered in a TechNet article. John Howard also has a very thorough blog on remote administration.

Miscellaneous

Issue #1

You may experience one of the following issues on a Windows Server 2003 virtual machine:

· An Event ID 1054 is logged to the Application Event log:

Event ID: 1054
Source: Userenv
Type: Error
Description:
Windows cannot obtain the domain controller name for your computer network. (The specified domain either does not exist or could not be contacted). Group Policy processing aborted.

· A negative ping time is displayed when you use the ping command.

· Perfmon shows high disk queue lengths

Cause: This problem occurs when the time-stamp counters (TSC) for different processor cores are not synchronized.

Resolution: Perform the steps documented in KB938448.

As always, we hope this has been informative for you.

BTW – Did I mention we are strongly recommending installing Windows Server 2008 SP2 on all Hyper-V server? Have a good one!

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

DPM 2007 - Troubleshooting protection for Hyper-V

tomac — Fri, 31 Jul 2009 00:22:03 GMT

This post is about Windows Server 2008 with the Hyper-V role installed, that are being protected by System Center Data Protection Manager 2007. There may be one or many Virtual Machines on each Host/Parent Partition, and they may be running Windows 2003 and/or Windows 2008. Supposing the DPM Agent is installed only on the Host/Parent partition of the Hyper-V server, you may find that DPM jobs fail intermittently on the 2003 VM’s, but the 2008 VM’s successfully complete. The following error may be encountered:

Type: Recovery point
Status: Failed
Description: DPM encountered a retryable VSS error. (ID 30112 Details:
Unknown error (0x800423f3) (0x800423F3))
End time: 4/23/2009 3:37:22 PM
Start time: 4/23/2009 3:36:38 PM
Time elapsed: 00:00:44
Data transferred: 0 MB
Cluster node -
Recovery Point Type Express Full
Source details: \Backup Using Child Partition Snapshot\%ServerName%
Protection group: %ProtectionGroupName%

We found these jobs fail when the Volume Shadow Copy Service (VSS service) on the guest VM is in a “Stopping” state and the only way to get the service in a good condition is to kill the process or reboot the VM. If the VSS service is in this “Stopping” state the next DPM job will fail. But if you first verify the VSS service is in a correct state (running or stopped) the DPM job will run successfully. However, once the DPM job is done you may see the VSS service stuck in the “Stopping” state. This service should automatically stop after 3 minutes of idle time but intermittently it may not stop. We experienced this behavior across several Hosts and almost all VM’s in a particular environment. The behavior is random but a few VM’s experience the problem more frequently than others. We also noticed if the VM is rebooted it will likely work without issues for a few days before the problem re-occurs.

When using vssadmin Windows Server command (see http://technet.microsoft.com/en-us/library/cc754968(WS.10).aspx), it appeared the “Microsoft Hyper-V VSS Writer” on the host was in a “Failed” state with a “Retryable” Last error state when the job fails. Ordinarily the writer will show a “Stable” state, and “No error” as follows.

When the jobs fail, the above command will return:

Writer name: 'Microsoft Hyper-V VSS Writer'
Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
Writer Instance Id: {59f449f9-2413-494d-b679-965bc56129fd}
State: [8] Failed
Last error: Retryable error

After installing Service Pack 2 for Windows 2008, or hotfix KB967560 (see Resolution section below) and running another DPM job on a different VM that has the VSS service in a non-stopping state, the job will run succesfully and place the Hyper-V VSS Writer back into a “Stable” state.

Quick reference for different possible scenarios:

VM in good state + Host in good state = Good backup
VM in bad state + Host in good state = Failed backup
VM in bad state + Host in bad state = Failed job
VM in good state + Host in bad state = Good job

Another possible symptom, when a DPM job is running you may notice on the Hyper-V Management screen next to the VM it displays this message: “Creating VSS Snapshot Set…”. This will continue to be displayed and when looking at the Volume Shadow Copy Service inside the W2K3 VM you may notice the service is stopped. Additionally, when running “vssadmin list writers” on the Host a message is displayed but no writers are visible:

“Waiting for responses. These may be delayed if a shadow copy is being prepared.”

When this condition occurs you may not be able cancel the DPM job. When trying to cancel the DPM job you may get the following in the detailed pane:

Type: Recovery point
Status: Attempting to cancel
End time: -
Start time: 4/28/2009 10:00:21 AM
Time elapsed: 01:01:22
Data transferred: -
Cluster node -
Recovery Point Type Express Full
Source details: \Backup Using Child Partition Snapshot\%Servername%
Protection group: %ProtectionGroupName%

Looking in the System Event log on the W2K3 VM during the times when the DPM jobs failed it may be clean. But the Application event log may be filled with the VSS errors below:

Event Type: Error
Event Source: VSS
Event Category: None
Event ID: 8193
Date: 2/24/2009
Time: 8:46:34 AM
User: N/A
Computer: %SystemName%
Description:
Volume Shadow Copy Service error: Unexpected error calling routine IEventSystem::Store. hr = 0x80040206.

Event Type: Error
Event Source: VSS
Event Category: None
Event ID: 12302
Date: 2/24/2009
Time: 5:58:49 AM
User: N/A
Computer: %SystemName%
Description:
Volume Shadow Copy Service error: An internal inconsistency was detected in trying to contact shadow copy service writers. Please check to see that the Event Service and Volume Shadow Copy Service are operating properly.

When viewing the System and Application event logs on the DPM server neither have any entries for the same times as the job failures. But the DPM event log may have the following entry:

Event Type: Error
Event Source: DPM-EM
Event Category:None
Event ID: 2
Date: 2/19/2009
Time: 9:20:20 AM
User: N/A
Computer: %DPMServername%
Description:
Creation of recovery points for Backup Using Child Partition Snapshot\%ProtectedServerName-VM% on %HOSTName% have failed. The last recovery point creation failed for the following reason: (ID: 3159) DPM encountered a retryable VSS error. (ID: 30112)
DPM ID: 2^|^%DPMServername%^|^Recovery point creation failures^|^DPM^|^Backup^|^%HOSTName% ^|^a48c6c91-f4ae-4ed3-b5da-a3c22d980a48

RESOLUTION

The Hyper-v issue seems to be the result of the underlying state of VSS. VSS is hung in the "stopping" state because the registry writer is hung attempting to unregister a COM+ event subscription. This is a subscription for listening for COM messages from other VSS components. When analyzing the logs captured during the problem it was found the unsubscribe function had been waiting eight minutes when the trace ended (and still had not completed).

It could be that the machine is having COM issues. The VSS service is not going to be successful with processing subsequent jobs until this unsubscribe completes. If you experience any of the symptoms mentioned above, you should perform all of the action items noted below.

Action Item #1:

Verify all the Prerequisites are met for protecting Hyper-V with DPM:

Prerequisites and Known Issues with Hyper-V Protection
http://technet.microsoft.com/en-us/library/dd347840.aspx

Action Item #2:

Online backups are not possible if any of the following conditions are not met. Verify that all the W2K3 VM’s meet these requirements:

1. Hyper-V Integration components is installed and is running the latest version

NOTE: (On the Host/Parent partition you can check VMMS.exe = 6.0.6001.22352 (or newer) and in the guest, check vmbus.sys version 6.0.6001.22334 (or newer)

2. No Dynamic disks inside the guest.

3. All volumes are NTFS

4. All NTFS volumes must be >1GB and have >300MB free space.

5. Shadow copies within the VM are on the same volume or are Disabled

6. VM is in running state.

NOTE: Offline Backups of Windows 2000 Guest VMs fail. Cause: A synthetic SCSI Controller was configured for the VM with no drives attached. Windows 2000 Guests do not support the SCSI Controller, so it is not needed.

Action Item #3:

The root cause of symptoms noted in the Problem section appear to be COM related. After verifying the action items above install the following COM updates:

KB934016 "Availability of Windows Server 2003 Post-Service Pack 2 COM+ 1.5 Hotfix Rollup Package 12"

http://support.microsoft.com/default.aspx?scid=kb;EN-US;934016

KB965230 "FIX: The COM+ Event System does not deliver timely or reliable statistics to subscribers of the IComTrackingInfoEvents event interface in Windows Server 2003"
http://support.microsoft.com/default.aspx?scid=kb;EN-US;965230

KB968447 "The COM+ Event System stops processing the query for matching subscriptions when it detects a corrupted subscription on a Windows Server 2003-based computer"
http://support.microsoft.com/default.aspx?scid=kb;EN-US;968447

Action Item #4:

Install the following two W2K3 VSS updates on the W2K3 virtual machines:

KB940349 “Availability of a Volume Shadow Copy Service (VSS) update rollup package for Windows Server 2003 to resolve some VSS snapshot issues”

http://support.microsoft.com/default.aspx?scid=kb;EN-US;940349

KB969219 “RPC 0x800706ba and 0x800706bf errors occur when backup software tries to create VSS shadow copies on a computer that is running Windows Server 2003 SP2”
http://support.microsoft.com/default.aspx?scid=kb;EN-US;969219

Install the latest VSS/Volsnap update on the W2K3 VM’s. If the Host is also running W2K3 it will be a good idea to also install:
KB967551 “Rollup update for the volsnap.sys driver in Windows Server 2003”
http://support.microsoft.com/default.aspx?scid=kb;EN-US;967551

Action Item #5:

If possible, install W2K8 SP2 since it will include the most recent Hyper-V writer updates. But, there are situations where installing SP2 will not be an option. As an alternative you can install KB967560 and KB971394 on the Windows Server 2008 Host machine.

KB967560 update is more recent then KB959978 which does address a known issue when you run a Windows Server 2003-based virtual machine on a Windows Server 2008 Hyper-V-based computer:

KB967560 “A backup operation fails on a two-node failover cluster that is running Windows Server 2008 after one of the disk resources is moved”

http://support.microsoft.com/default.aspx?scid=kb;EN-US;967560

KB971394 "A backup of virtual machines fails when you use the Hyper-V VSS writer to back up virtual machines concurrently on a computer that is running Windows Server 2008"
http://support.microsoft.com/default.aspx?scid=kb;EN-US;971394

How to obtain the latest service pack for Windows Server 2008
http://support.microsoft.com/kb/968849

ADDITIONAL INFORMATION:

Virtualization with Hyper-V: Supported Guest Operating Systems
http://www.microsoft.com/windowsserver2008/en/us/hyperv-supported-guest-os.aspx

Author:
Tom O’Malley
Microsoft Enterprise Support
Sr. Support Escalation Engineer

Technorati Tags: Data Protection Manager 2007,Hyper-V,Windows Server 2008

Expected Snapshot Merge Behavior for a Highly Available VM

jeffhugh — Fri, 29 May 2009 15:22:03 GMT

Hello my name is Sean Dwyer, and I'm a Support Escalation Engineer working in the Windows CORE team here at Microsoft.

While working with snapshots that are attached to a highly available VM in a Cluster, you may notice after deleting a snapshot, it does not merge as expected. You'll notice the merge process almost immediately ends and the VM begins to restart.

Let's explore a scenario I ran myself into the other day and then I'll explain why you may see this behavior.

Fig. 1.

Here I have configured a HA-VM of XP SP2 in Fig 1. and it is Online and happy, within the Cluster.

Fig. 2.

Switching to the Hyper-V Management MMC in Fig. 2, I've decided that my testing is over with this VM, and I need to clean up the snapshots. The 'Now' state is where I want the VM to remain, so I'm going to issue a Delete Snapshot Subtree command.

Fig. 3.

I choose 'Yes', and the snapshots are removed from the VM in Fig. 3.
Next, I choose to shut down the VM in Fig. 4, as I want to commit the merge now, and not wait until later.

Fig. 4.

The Merge process starts, but immediately finishes and the VM is restarting as seen in Fig. 5 and Fig. 6.

Fig. 5.

Fig. 6.

The merge didn't complete! What just happened?

Failover Cluster is doing its job!

When deleting a snapshot for a VM that is configured as a Highly Available Resource, you're taking action against the VM outside of the Cluster Management UI, and therefore, the Cluster service considers any shutdown events, or reboots, a failure of the resource and takes appropriate action.

In my example, the default behavior is restarting the VM as shown in Fig.7.

Fig. 7.

The end result is that the snapshot merge process has NOT taken place and I've still got AVHDs out there shown in Fig. 8.

Fig. 8.

So, what do we do, to get the Snapshots merged successfully? Easy!

We need to configure the Clustered VM Resource to allow the Snapshot Merge process to complete without being interrupted.

Open up the Properties of the VM, and then select the Offline Actions Tab.

You'll note, in Fig. 9, the default behavior is to Save the VM.

Fig. 9.

In Fig. 10, let's change this default behavior temporarily to Shutdown.

Fig. 10.

Once the change has been made, you can then choose to shutdown the VM either through Hyper-V Manager or through the Clustering UI, and the Snapshot Merge process will begin.

Once the Merge completes, reset the behavior of the VM in the Offline Actions Tab for the VM back to Save as shown in Fig. 11.

Fig. 11.

Once you start the VM, you'll be back in business!

I hope this blog post will help you continue to use our Clustering and Virtualization products successfully!

Sean Dwyer
Support Escalation Engineer
Microsoft Enterprise Platforms Support

Top Issues for Microsoft Support for Windows Server 2008 Hyper-V (Q3)

jeffhugh — Wed, 27 May 2009 17:24:55 GMT

It is time to update everyone on the issues our support engineers have been seeing for Hyper-V for the past quarter. The issues are categorized below with the top issue(s) in each category listed with possible resolutions and additional comments as needed. I think you will notice that the issues for Q3 have not changed much from Q1\Q2. Hopefully, the more people read our updates, the fewer occurrences we will see for some of these and eventually they will disappear altogether. There will probably be one more blog for the Q4 results. Additionally, I would like to mention that we are highly recommending the installation of Windows Server 2008 Service Pack 2 on all servers running the Hyper-V Role.

Deployment\Planning

Issue #1

Customers looking for Hyper-V documentation.

Installation Issues

Issue #1

A customer was experiencing an issue on a pre-release version of Hyper-V.

Resolution: Upgrade to the release version (KB950050) of Hyper-V.

Issue #2

After the latest updates off Windows Update are installed or KB950050 is installed, virtual machines fail to start with one of the following error messages:

An error occurred while attempting to chance the state of the virtual machine vmname .
‘ vmname ’ failed to initialize.
Failed to read or update VM configuration.

Cause: This issue occurs because virtual machine configurations that were created in the beta version of the Hyper-V are incompatible with later versions of the Hyper-V.

Resolution: Perform the steps documented in KB949222.

Issue #3

After the Hyper-V role is installed, a customer creates a virtual machine but it fails to start with the following error:

The virtual machine could not be started because the hypervisor is not running

Cause: Hardware virtualization or DEP was disabled in the BIOS.

Resolution: Enable Hardware virtualization or DEP in the BIOS. In some cases, the server may need to be physically shutdown in order for the new BIOS settings to take effect.

Virtual Devices\Drivers

Issue #1

Synthetic NIC was listed as an unknown device in device manager.

Cause: Integration Components needed to be installed.

Resolution: Install Integration Components (IC) package in the VM.

Issue #2

Stop 0x00000050 on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: This issue can occur if a Hyper-V virtual machine is configured with a SCSI controller but no disks are attached.

Resolution: Perform the steps documented in KB969266.

Issue #3

Stop 0x0000001A on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: Vid.sys

Resolution: Install hotfix KB957967 to address this issue.

Snapshots

Issue #1

Snapshots fail to merge with error 0x80070070

Cause: Low disk space.

Resolution: Free up disk space to allow the merge to complete.

Issue #2

Snapshots were deleted

Cause: The most common cause is that a customer deleted the .avhd files to reclaim disk space (not realizing that the .avhd files were the snapshots).

Resolution: Restore data from backup.

For more information on Snapshots, please refer to the Snapshot FAQ: http://technet.microsoft.com/en-us/library/dd560637.aspx.

Issue #3

Snapshots were lost

Cause: Parent VHD was expanded (not supported). If snapshots are associated with a virtual hard disk, the parent vhd file should never be expanded. This is documented in the Edit Disk wizard:

Resolution: Restore data from backup.

Integration Components

Issue #1

A Windows 2000 (SP4) virtual machine with the Integration Components installed may shut down slowly.

Cause: This problem is caused by a bug in the Windows Software Trace Pre-Processor (WPP) tracing macro (outside of Hyper-V).

Resolution: KB959781 documents the workarounds for this issue on Server 2008.

Issue #2

Attempting to install the Integration Components on a Server 2003 virtual machine fails with the following error:

Unsupported Guest OS

An error has occurred: The specified program requires a newer version of Windows.

Cause: Service Pack 2 for Server 2003 wasn’t installed in the virtual machine.

Resolution: Install SP2 in the Server 2003 VM before installing the integration components.

Virtual machine State and Settings

Issue #1

You may experience one of the following issues on a Windows Server 2008 system with the Hyper-V role installed or Microsoft Hyper-V Server 2008:

When you attempt to create or start a virtual machine, you receive one of the following errors:

· The requested operation cannot be performed on a file with a user-mapped section open. ( 0x800704C8 )

· ‘VMName’ Microsoft Synthetic Ethernet Port (Instance ID

{7E0DA81A-A7B4-4DFD-869F-37002C36D816}): Failed to Power On with Error 'The specified network resource or device is no longer available.' (0x80070037).

· The I/O operation has been aborted because of either a thread exit or an application request. (0x800703E3)

Virtual machines disappear from the Hyper-V Management Console.

Cause: This issue can be caused by antivirus software that is installed in the parent partition and the real-time scanning component is configured to monitor the Hyper-V virtual machine files.

Resolution: Perform the steps documented in KB961804.

Issue #2

Creating or starting a virtual machine fails with the following error:

'General access denied error' (0x80070005).

Cause: This issue can be caused by the Intel IPMI driver.

Resolution: Perform the steps documented in KB969556.

Issue #3

Virtual machines have a state of "Paused-Critical"

Cause: Lack of free disk space on the volume hosting the .vhd or .avhd files.

Resolution: Free up disk space on the volume hosting the .vhd or .avhd files.

High Availability (Failover Clustering)

Issue #1

How to configure Hyper-V on a Failover Cluster.

Resolution: A step-by-step guide is now available which covers how to configure Hyper-V on a Failover Cluster.

Issue #2

Virtual machine settings that are changed on one node in a Failover Cluster are not present when the VM is moved to another node in the cluster.

Cause: The "Refresh virtual machine configuration" option was not used before attempting a failover.

Resolution: When virtual machine settings are changed on a VM that’s on a Failover Cluster, you must select the ‘Refresh virtual machine configuration’ option before the VM is moved to another node. There is a blog that discusses this.

Backup (Hyper-V VSS Writer)

Issue #1

You may experience one of the following symptoms if you try to backup a Hyper-V virtual machine:

· If you back up a Hyper-V virtual machine that has multiple volumes, the backup may fail. If you check the VMMS event log after the backup failure occurs, the following event is logged:

Log Name: Microsoft-Windows-Hyper-V-VMMS-Admin

Source: Microsoft-Windows-Hyper-V-VMMS

Event ID: 10104

Level: Error

Description:

Failed to revert to VSS snapshot on one or more virtual hard disks of the virtual machine '%1'. (Virtual machine ID %2)

Resolution: An update (KB959962) is now available to address issues with backing up and restoring Hyper-V virtual machines.

Issue #2

How to backup virtual machines using Windows Server Backup

Resolution: Perform the steps documented in KB958662.

Virtual Network Manager

Issue #1

Virtual machines are unable to access the external network.

Cause: The virtual network was configured to use the wrong physical NIC.

Resolution: Configure the external network to use the correct NIC.

Issue #2

Network connectivity issues

Cause: NIC teaming software

Resolution: Remove the NIC teaming software. Our support policy for NIC Teaming with Hyper-V is now documented in KB968703.

Issue #3

Customers inquiring if Hyper-V supports NIC Teaming.

Resolution: Our support policy for NIC Teaming with Hyper-V is now documented in KB968703.

Hyper-V Management Console

Issue #1

How to manage Hyper-V remotely.

Resolution: The steps to configure remote administration of Hyper-V are covered in a TechNet article. John Howard also has a very thorough blog on remote administration.

Import/Export

Issue #1

Importing a virtual machine may fail with the following error:

A Server error occurred while attempting to import the virtual machine. Failed to import the virtual machine from import directory <Directory Path>. Error: One or more arguments are invalid (0x80070057).

Resolution: Perform the steps documented in KB968968.

Miscellaneous

Issue #1

You may experience one of the following issues on a Windows Server 2003 virtual machine:

· An Event ID 1054 is logged to the Application Event log:

· A negative ping time is displayed when you use the ping command.

· Perfmon shows high disk queue lengths

Cause: This problem occurs when the time-stamp counters (TSC) for different processor cores are not synchronized.

Resolution: Perform the steps documented in KB938448.

As always, we hope this has been informative for you.

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

Issues after moving Virtual Machines from one Hyper-V parent (host) to another

tomac — Sat, 18 Apr 2009 20:25:43 GMT

If you move one or more of your virtual machines (VM) from one Hyper-V parent to another and the VM begins experiencing issues, it could be because the version level of Hyper-V between the two parents is different, and thus the version of the Integration Services may be different. This can result in some strange and unwanted behavior.

I recently experienced an issue in which I moved a VM from one parent that I was planning on rebuilding to another. The VM started and ran fine on the new parent system, but after 30 minutes or so, the virtual network adapter lost connection to the network and eventually was changed to a status of Disabled in Device Manager. Uninstalling and re-installing the adapter did not resolve the problem.

I eventually checked the version of the driver for the virtual network adapter and it displayed a strange version of 21.x.x.x. (I don’t recall the exact version), which is not at all close to what it should be. Since this driver is provided by the Integration Services, I uninstalled them from the VM, restarted it, and then installed them again. This resolved the problem. The network driver version is now 6.0.6001.18010, which is the current version.

The version of Integration Services is closely tied to the version of Hyper-V that is installed. Other issues may occur if these are mismatched, the issue with the network adapter was the first one I experienced. If you move VMs from a parent that is running the beta or RC version of Hyper-V, remember to uninstall the Integration Services (listed as Hyper-V Guest Components in Add or Remove Programs), restart the VM, and then install the version from the new parent.

Author: Kevin McNiel
Senior Support Engineer
Microsoft Corporation

Top Issues for Microsoft Support for Windows Server 2008 Hyper-V (Q2)

jeffhugh — Mon, 16 Feb 2009 20:17:29 GMT

It is time to update everyone on the types of issues our support engineers have been seeing for Hyper-V. The issues are categorized below with the top issue(s) in each category listed with possible resolutions and additional comments as needed. I think you will notice that the issues for Q2 have not changed much from Q1. Hopefully, the more people read our updates, the fewer occurrences we will see for some of these and eventually they will disappear altogether.

Deployment\Planning

Issue #1

Customers looking for Hyper-V documentation

Installation Issues

Issue #1

After the Hyper-V role is installed, the customer creates a virtual machine, but it fails to start with the following error:

The virtual machine could not be started because the hypervisor is not running.

Cause: Hardware virtualization or DEP was disabled in the BIOS.

Resolution: Enable Hardware virtualization or DEP in the BIOS. In some cases, the server needs to be physically shutdown in order for the new BIOS settings to take effect.

Issue #2

System hangs on restart at "Configuring Updates Stage 3 of 3" after the Hyper-V role is enabled, disabled, or updated.

Cause: This issue can be caused by the HP Network Configuration utility.

Resolution: Perform the steps documented in KB950792.

Issue #3

Customer was experiencing an issue on a pre-release version of Hyper-V.

Resolution: Upgrade to the release version (KB950050) of Hyper-V.

Virtual Devices\Drivers

Issue #1

Synthetic NIC was listed as an unknown device in device manager.

Cause: Integration Components need to be installed.

Resolution: Install the Integration Services by opening the Virtual Machine Connection window, and then select Insert Integration Services Setup Disk on the Action menu.

Issue #2

Stop 0x0000001A on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: Vid.sys driver issue.

Resolution: Install hotfix KB957967 to address this issue.

Issue #3

Stop 0x00000050 on a Microsoft Hyper-V Server 2008 or Server 2008 system with the Hyper-V role installed.

Cause: Storvsp.sys driver issue.

Resolution: If a VM has a SCSI controller with no disks attached, this bugcheck can occur. The resolution is to remove any SCSI controllers which don’t have disks attached. This issue is fixed in SP2.

Issue #4

After you move a Windows Vista or Windows Server 2008 virtual machine from Virtual PC or Virtual Server, the Vmbus device fails to load. When you check the properties of the device in device manager, the device status displays one of the following messages:

This device cannot find enough free resources that it can use. (Code 12).

This device cannot start. (Code 10).

Cause: This issue occurs because the Windows Vista or Windows Server 2008 virtual machine is using the incorrect HAL.

Resolution: Perform the steps documented in KB954282.

Issue #5

Unable to associate the virtual COM port to a physical COM port.

Cause: By design (documented in the help file).

Snapshots

Issue #1

Snapshots were lost

Cause: Parent VHD was expanded. If snapshots are associated with a virtual hard disk, the parent vhd file should never be expanded. This is documented in the Edit Disk wizard:

Resolution: Restore data from backup.

Issue #2

Snapshots were deleted.

Cause: The most common cause is that the customer deleted the .avhd files to reclaim disk space (not realizing that the .avhd files were the snapshots).

Resolution: Restore data from backup.

Integration Components

Issue #1

A Windows 2000 (SP4) virtual machine with the Integration Components installed may shut down slowly.

Cause: This problem is caused by a bug in the operating system (outside of Hyper-V).

Resolution: KB959781 documents the workarounds for this issue on Server 2008. The issue is fixed in Windows Server 2008 R2.

Issue #2

Attempting to install the Integration Components on a Server 2003 virtual machine fails with the following error:

Unsupported Guest OS

An error has occurred: The specified program requires a newer version of Windows.

Cause: The most common cause is that Service Pack 2 for Server 2003 wasn’t installed in the virtual machine..

Resolution: Install SP2 in the Server 2003 VM before you install the integration components.

Virtual machine State and Settings

Issue #1

You may experience one of the following issues on a Windows Server 2008 system with the Hyper-V role installed or Microsoft Hyper-V Server 2008:

When you attempt to create or start a virtual machine, you receive one of the following errors:

The requested operation cannot be performed on a file with a user-mapped section open. ( 0x800704C8 )
‘VMName’ Microsoft Synthetic Ethernet Port (Instance ID {7E0DA81A-A7B4-4DFD-869F-37002C36D816}): Failed to Power On with Error 'The specified network resource or device is no longer available.' (0x80070037).
The I/O operation has been aborted because of either a thread exit or an application request. (0x800703E3)

Virtual machines disappear from the Hyper-V Management Console.

Cause: This issue can be caused by antivirus software that is installed in the parent partition and the real-time scanning component is configured to monitor the Hyper-V virtual machine files.

Resolution: Perform the steps documented in KB961804.

Issue #2

Creating or starting a virtual machine fails with the following error:

General access denied error' (0x80070005)

Cause: This issue can be caused by the Intel IPMI driver.

Resolution: Perform the steps documented on Intel’s site.

High Availability (Failover Clustering)

Issue #1

How to configure Hyper-V on a Failover Cluster.

Resolution: A step-by-step guide is now available which covers how to configure Hyper-V on a Failover Cluster.

Issue #2

Virtual machine settings that are changed on one node in a Failover Cluster are not present when the VM is moved to another node.

Cause: The "Refresh virtual machine configuration" option was not used before attempting a failover.

Resolution: When virtual machine settings are changed on a VM that’s on a Failover Cluster, you must select the refresh virtual machine configuration option before the VM is moved to another node. There is a blog that discusses this.

Backup (Hyper-V VSS Writer)

Issue #1

You may experience one of the following symptoms if you try to backup a Hyper-V virtual machine:

· If you back up a Hyper-V virtual machine that has multiple volumes, the backup may fail. If you check the VMMS event log after the backup failure occurs, the following event is logged:

Log Name: Microsoft-Windows-Hyper-V-VMMS-Admin

Source: Microsoft-Windows-Hyper-V-VMMS

Event ID: 10104

Level: Error

Description:

Failed to revert to VSS snapshot on one or more virtual hard disks of the virtual machine '%1'. (Virtual machine ID %2)

Resolution: An update (KB959962) is now available to address issues with backing up and restoring Hyper-V virtual machines.

Virtual Network Manager

Issue #1

How to configure a virtual machine to use a VLAN.

Resolution: VLANs are discussed in the following blogs: http://blogs.msdn.com/virtual_pc_guy/archive/2008/03/10/vlan-settings-and-hyper-v.aspx and http://blogs.msdn.com/adamfazio/archive/2008/11/14/understanding-hyper-v-vlans.aspx

Hyper-V Management Console

Issue #1

How to manage Hyper-V remotely.

Resolution: The steps to configure remote administration of Hyper-V are covered in a TechNet article. John Howard also has a very thorough blog on remote administration.

As always, we hope this has been informative for you.

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

Top Issues for Microsoft Support for Windows Server 2008 Hyper-V

jeffhugh — Tue, 23 Dec 2008 16:42:27 GMT

Hyper-V Beta released as part Windows Server 2008. The final release of Hyper-V happened shortly after the Windows Server 2008 release and can be downloaded here. After a few months of supporting customers, we now have enough case data to report on the top issues being reported for Hyper-V. The issues are categorized below with the top issue(s) in each category listed with possible resolutions and additional comments as needed. These may change as time passes, but as of this post, this is how we see it here in CORE. As always, we welcome your comments.

Deployment\Planning

Issue #1

Customers looking for Hyper-V documentation.

Resolution: Information is provided on the Microsoft Hyper-V TechNet Library which includes links to several Product Team blogs. Additionally, the Microsoft Virtualization site contains information that can be used to get a Hyper-V based solution up and running quickly.

Issue #2

How to migrate virtual machines from Virtual Server 2005 to Hyper-V?

Resolution: The CORE Team blog provides tips and suggestions to help with the migration process.

Installation Issues

Issue #1

System hangs on restart at "Configuring Updates Stage 3 of 3" after the Hyper-V role is enabled, disabled, or updated.

Cause: HP Network Configuration Utility.

Resolution: Perform the steps documented in KB950792.

Issue #2

After the Hyper-V role is installed, a virtual machine fails to start with the following error:

The virtual machine could not be started because the hypervisor is not running

Cause: Hardware virtualization or Data Execution Prevention (DEP) was not enabled in the BIOS.

Resolution: Enable Hardware virtualization or DEP in the BIOS. In some cases, the server must be physically shutdown in order for the BIOS settings to take effect.

Virtual Devices\Drivers

Issue #1

A Synthetic NIC was listed as an unknown device in device manager.

Cause: Integration Components were not installed.

Resolution: Install Integration Components package in the VM.

Issue #2

Unable to associate the virtual COM port to a physical COM port.

Cause: By design.

Issue #3

Dynamic disks attached to the SCSI controller in a Windows Server 2003 virtual machine show as Offline on restart.

Cause: Storsvc is set to the incorrect start value in the registry.

Resolution: Perform the following step in the Guest OS registry:

Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storvsc

Change the "Start" value from 3 to 0.

Additional Comment: This has been fixed in Windows Server 2008 SP2.

Integration Components

Issue #1

Attempting to install the Integration Components in a Windows Server 2003 virtual machine fails with the following error:

Unsupported Guest OS
An error has occurred: The specified program requires a newer version of Windows

Cause: Service Pack 2 for Windows Server 2003 wasn’t installed in the virtual machine. You can hit this error for other OS’ that don’t have the appropriate service pack installed (Vista, Windows XP, etc..).

Resolution: Install SP2 in the Windows Server 2003 VM before installing the integration components.

Virtual Machine State and Settings

Issue #1

Virtual machines show a state of "Paused-Critical" in the Hyper-V Management Console

Cause: Lack of free disk space on the volume hosting the .vhd or .avhd files.

Resolution: Free up disk space on the volume hosting the .vhd or .avhd files.

Issue #2

When you attempt to create or start a virtual machine, you receive the following error:

The requested operation cannot be performed on a file with a user-mapped section open. (0x800704C8)

Cause: This issue can be caused by antivirus software that is installed in the parent partition and the real-time scanning component is configured to monitor files used by Hyper-V.

Resolution: Configure the real-time scanning component within the antivirus software to exclude the following files and directories:

Default virtual machine configuration directory (C:\ProgramData\Microsoft\Windows\Hyper-V)
Custom virtual machine configuration directories
Default virtual hard disk directory (C:\Users\Public\Documents\Hyper-V\Virtual Hard Disks)
Custom virtual hard disk directories
Snapshot directories
Vmms.exe
Vmwp.exe

Additional Comment: A KB article is forthcoming.

High Availability (Failover Clustering)

Issue #1

Virtual machine settings that are changed on one node in a Failover Cluster are not present when the VM is moved to another node.

Cause: The 'Refresh virtual machine configuration' option in the Failover Cluster Management interface was not used prior to moving the VM to another node in the cluster.

Resolution: When virtual machine settings are changed in a VM that’s running in a Failover Cluster, you must select the 'Refresh virtual machine configuration' option before the VM is moved to another node.

Additional Comment: We have a CORE blog which discusses this issue.

Issue #2

Customers looking for documentation on how to configure Hyper-V in a Failover Cluster.

Resolution: A step-by-step guide is available which covers how to configure Hyper-V in a Failover Cluster.

Hyper-V Snapshots

Issue #1

Snapshots associated with a VM are lost.

Cause: Parent VHD was expanded.

Resolution: Restore data from backup.

Additional Comments: There is a warning about this in the Edit Disk wizard which should not be ignored.

Issue #2

Virtual machine fails to boot.

Cause: Virtual machine had associated snapshots and to recover disk space the .avhd files were deleted.

Resolution: Restore data from backup.

Backup (Hyper-V VSS Writer)

Issue #1

How to backup virtual machines using Windows Server Backup (WSB).

Resolution: There is a CORE blog which discusses the steps needed to register the Hyper-V VSS writer with Windows Server Backup. A KB article has also been written.

Hyper-V Management Console

Issue #1

When remotely managing a Hyper-V Server and trying to perform a task such as creating a virtual machine or modifying virtual machine settings, you may receive the following error:

You might not have permission to perform this task

Cause: There are multiple causes for this error but the most common cause is that a beta version of the Hyper-V Management Console was being used to manage a Hyper-V server that was running the RTM build.

Resolution: Install the RTM version of the Hyper-V Management Console.

Additional Comment: There is a multi-part Product Group blog that discusses this error and provides several possible solutions which are scenario dependent.

Chuck Timon
Senior Escalation Engineer
Microsoft Enterprise Platforms Support

Installing A VM Operating System Using a Legacy Network Adapter and PXE-boot

jeffhugh — Tue, 25 Nov 2008 20:53:26 GMT

Virtual machines can be deployed to Hyper-V using Windows Deployment Services (WDS). To accomplish this requires the proper WDS infrastructure be in place and that the VM PXE boot using a Legacy Network Adapter. Windows Deployment Services can run on Windows Server 2003 or be installed as a Role in Windows Server 2008. It is not the purpose of this blog to detail setting up WDS but to document the process for entering information in Active Directory when using Pre-staged Computer Objects.

Windows Deployment Services can be configured to respond to all clients or only to known clients. Virtual machines configured for PXE boot using a Legacy Network Adapters will respond correctly when a WDS server is configured to respond to all clients. However, when the WDS server is configured to respond to only known clients, the Hyper-V server may not obtain a DHCP assigned IP address and be presented with a boot menu option. When a WDS server is configured to respond to only known clients, the VM computer account must be pre-staged in Active Directory. Part of configuring this Computer Account requires using a unique ID to identify the computer. There are two methods that can be used:

MAC address
Globally Unique ID (GUID)

To obtain this information from a VM, configure the VM to use a Legacy Network Adapter and then in the VM settings change the boot order such that the Legacy Network Adapter is listed first. Start the VM and then 'Pause' it to obtain the above pieces of information as shown here:

In the above screenshot, we see both the VM MAC address (assigned from the Hyper-V pool of MAC addresses) and its GUID.

The Information is entered in the Remote Install tab for the Properties of the pre-staged Computer Object in Active Directory as shown here:

In the screenshot above, I used the MAC address obtained by booting the VM. The MAC address must be preceded by twenty (20) zeroes to be considered valid. If the choice is to use the GUID, the first 16 bits must be reversed when entering the information in the Remote Install tab. For example, the GUID displayed when booting the VM was - E767FFB0-82D2-4AE5-9A88-ABBB6322BC5E. When entering it in the Remote Install tab you would have to enter - B0FF67E7D282E54A9A88ABBB6322BC5E. The highlighted portion has been reversed (first 16 entries). After selecting Apply, the first 16 bits will be reversed and the entry will appear as it did during the PXE boot. There is a KB article that explains the reason why the entry may appear differently:

KB228905 - GUID of Pre-Staged Computer Appears Different Than as Typed.

With the information entered for the pre-staged Computer Object, the VM should boot correctly and you will be presented with a menu selection (depending on how many images were added to the WDS server) for completing the installation.

I hope you found this Hyper-V tidbit informative should you decide to use WDS to deploy VMs in Hyper-V. As always, we would appreciate your feedback.

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

Configuring Pass-through Disks in Hyper-V

jeffhugh — Fri, 24 Oct 2008 19:33:47 GMT

A question the CORE Team gets asked frequently deals with configuring Hyper-V Guest with Pass-through disks. In this blog I will cover this topic.

Pass -through Disk Configuration

Hyper-V allows virtual machines to access storage mapped directly to the Hyper-V server without requiring the volume be configured. The storage can either be a physical disk internal to the Hyper-V server or it can be a Storage Area Network (SAN) Logical Unit (LUN) mapped to the Hyper-V server. To ensure the Guest has exclusive access to the storage, it must be placed in an Offline state from the Hyper-V server perspective. Additionally, this raw piece of storage is not limited in size so, hypothetically, it can be a multi-terabyte LUN.

After storage is mapped to the Hyper-V server, it will appear as a raw volume and will be in an Offline state (depending on the SAN Policy (Figure 1-1)) as seen in Figure 1.

Figure 1: Raw disk is Offline

Figure 1-1 SAN Mode determination using diskpart.exe

I stated earlier that a disk must be Offline from the Hyper-V servers' perspective in order for the Guest to have exclusive access. However, a raw volume must first be initialized before it can be used. To accomplish this in the Disk Management interface, the disk must first be brought Online. Once Online, the disk will show as being Not Initialized (Figure 2).

Figure 2: Disk is Online but Not Initialized

Right-click on the disk and select Initialize Disk (Figure 3).

Figure 3: Initialize the disk

Select either an MBR or GPT partition type (Figure 4).

Figure 4: Selecting a partition type

Once a disk is initialized, it can once again be placed in an Offline state. If the disk is not in an Offline state, it will not be available for selection when configuring the Guest's storage.

In order to configure a Pass-through disk in a Guest, you must select Attach a virtual disk later in the New Virtual Machine Wizard (Figure 5).

Figure 5: Choosing to attach a virtual disk later

If the Pass-through disk will be used to boot the operating system, it must be attached to an IDE Controller. Data disks can take advantage of SCSI controllers. In Figure 6, a Pass-through disk is attached to IDE Controller 0.

Figure 6: Attaching a pass-through disk to an IDE Controller

Note: If the disk does not appear in the drop down list, ensure the disk is Offline in the Disk Management interface (In Server CORE, use the diskpart.exe CLI).

Once the Pass-through disk is configured, the Guest can be started and data can placed on the drive. If an operating system will be installed, the installation process will properly prepare the disk. If the disk will be used for data storage, it must be prepared in the Guest operating system before data can be placed on it.

If a Pass-through disk, being used to support an operating system installation, is brought Online before the Guest is started, the Guest will fail to start. When using Pass-through disks to support an operating system installation, provisions must be made for storing the Guest configuration file in an alternate location. This is because the entire Pass-through disk is consumed by the operating system installation. An example would be to locate the configuration file on another internal drive in the Hyper-V server itself. Or, if it is a cluster, the configuration file can be hosted on a separate cluster providing highly available file services. Be aware that Pass-through disks cannot be dynamically expanded. Additionally, when using Pass-through disks, you lose the capability to take snapshots, and finally, you cannot use differencing disks with Pass-through disks.

Note: When using Pass-through disks in a Windows Server 2008 Failover Cluster, you must have the update documented in KB951308: Increased functionality and virtual machine control in the Windows Server 2008 Failover Cluster Management console for the Hyper-V role installed on all nodes in the cluster.

This completes our discussion. I hope you will find this information useful and share it with your colleagues.

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

Upgrade error when using Select/Action Pack media on a Hyper-V VM

jeffhugh — Mon, 22 Sep 2008 17:29:21 GMT

You may encounter the following dialog box with attempting to upgrade an existing Operating System

The text of the dialog box reads:

Upgrade has been disabled

The upgrade cannot be started because you are running a 64-bit version of Windows and are trying to upgrade 32-bit version. Cancel this upgrade and start over with a 64-bit version of Windows
The upgrade cannot be started because you are running a 32-bit version of Windows and are trying to upgrade 64-bit version. Cancel this upgrade and start over with a 32-bit version of Windows

Possible Reason: You may be using Select Media or Action Pack media (DVD or ISO).

Select and Action Pack media are built with DVD boot menus that prompt for the user to choose which OS installation they want to install. Once that choice is made, the media continues to boot into text mode setup for that choice. This media is not capable of being used as a source for upgrades due to this menu and you will encounter this message.
To upgrade a VM, use an ISO or DVD with an individually available OS.

For more information about the Action Pack program, visit https://partner.microsoft.com/40013779

For more information about the Microsoft Select program, visit http://www.microsoft.com/licensing/programs/sel/default.mspx

Sean Dwyer
Senior Support Engineer
Microsoft Enterprise Platforms Support

Migrating to Hyper-V from Virtual Server or Virtual PC - Tips and Suggestions

jeffhugh — Fri, 19 Sep 2008 15:46:49 GMT

Now that you’ve decided to take the leap and migrate your Virtual Server 2005 R2 or Virtual PC environment to Windows Server 2008 Hyper-V; Welcome! I know you’re going to love it!

Some of the hurdles that you can run into may be a little worrisome, but we promise after you read through this, you’ll have the knowledge you will need to conceive a well thought out migration plan.

There are several step-by-step guides out there that walk you through the points and clicks needed to get the migration done, but the focus of this blog is to work through some of the steps that will help in the migration process. Here we go!

1. Before migrating Virtual Machines (VM)s from Virtual Server 2005 R2 SP1 or Virtual PC, you are going to want to make sure that the machines can take advantage of the Hyper-V Integration Services. Integration Services are software components that are installed in a guest running in a Hyper-V Child partition that allows the guest to more effectively integrate with the Parent partition and the hypervisor.

For example, that Windows-for-Workgroups 3.11 VM you’ve been nursing along won’t be able to take full advantage of the features in Hyper-V, however, these Operating Systems can:

Windows XP SP3 (x86 & x64)
Windows Vista SP1 (x86, & x64)
Windows Server 2003 SP2 (x86 & x64)
Window Server 2008 (x86 & x64)

Other OS’s can run in Hyper-V but they may not be able to take advantage of the Integration Services and will have to rely on legacy or 'emulated' device support. It is recommended that all pre-requisites (Service packs) be downloaded and installed before beginning the migration to Hyper-V.

2. Once you’ve determined which VMs you want to migrate, you will want to uninstall all VM Additions before migrating to Hyper-V.

If you do not remove the VM Additions before migrating to Hyper-V, you may have to move the virtual machine back to Virtual Server or Virtual PC to remove them. If you are running VM Additions which are at least version 13.813, then you will be able to uninstall them after migrating to Hyper-V. Earlier versions cannot be uninstalled from the virtual machine after it is migrated to hyper-V.

3. The next thing you may want to check is HAL compatibility. For example, this HAL is compatible:

An MPS Uniprocessor PC HAL is not, and would be upgraded when the Integrated Services are installed.

If you have a non-ACPI HAL in the VM, you may change it prior to the migration. By default, Hyper-V will install an APIC MP HAL when the Integration Services are installed in the Guest. If you choose to move the VM over to Hyper-V while it has a non ACPI HAL, you will be prompted to upgrade when you first start the installation of the ICs.

Note: Keep in mind that changing the HAL in an OS will usually trigger an OS re-activation.

4. Another thing to keep in mind is what you plan on doing with the network adapter(s) installed in the VM. If you do not have a specific need to use the Intel 21140 NIC under Hyper-V, then you should also remove that device before migration.

If you do not remove this NIC, and then install the Integrated Services, everything will appear to work just fine, however, when you try to reset your static IP information using a new Synthetic NIC which is installed (provided all pre-requisites have been met (refer to Step #1),you may see the following error message:

If you encounter this scenario, follow the steps in this article and remove the old NIC. This will free up the settings to be used by the new NIC. http://support.microsoft.com/default.aspx?scid=kb;EN-US;269155

5. You must make some storage preparations as well. Since Hyper-V does not use Undo Disks (*.vud files), you must 'commit' or 'discard' them before migrating to Hyper-V. For information on Undo disks, visit http://technet.microsoft.com/en-us/library/cc720325.aspx.

Additionally, we suggest compacting any Dynamically Expanding VHDs. For more information on compacting virtual hard disks, visit - http://technet.microsoft.com/en-us/library/cc708317.aspx

Once all of the above steps have been completed, you are ready to physically move the VHD files to the Hyper-V server or a temporary location. Remember, only the VHD can be used by Hyper-V. All of the other files used by Virtual PC or Virtual Server are incompatible with Hyper-V.

Good luck!

Sean Dwyer
Senior Support Engineer
Microsoft Enterprise Platforms Support

Expanding disks attached to Hyper-V VMs may not reflect adjusted size immediately on WS2008

jeffhugh — Thu, 18 Sep 2008 14:34:57 GMT

If you Inspect the disk in Hyper-V Manager that you just altered it will show the correct new maximum size however.

Even though the disk is a Dynamically Expanding type disk, we still need to tell the Operating System about the container size change. If you look in Storage Manager, you'll see the new unallocated space:

To take advantage of the newly allocated space, simply right click on the container and choose Extend Volume:

Make any size adjustments to the total space to extend, then choose Next

Verify the total size is what you want, and click Finish

Enjoy the extra new space on the VHD!

Windows Server 2003 Scenario:

The same behavior can be seen in Windows Server 2003, however the method to extend the volume is different than in 2008.

So when looking in Disk Management, we see the unallocated space available to expand into:

We have no Extend Volume option in 2003 though! Now what?

What we need to do is boot to WinPE and run Diskpart. What we need to do is boot to WinPE and run Diskpart or the Microsoft Diagnostic and Recovery Toolkit. The key point is that in order to extend a System managed partition, we need to be OUTSIDE of the OS. Understanding that there are third party and freeware tools that can accomplish the same task as WinPE or MS-DART 5.0, those options are beyond the scope of this posting.

If you are not able to obtain a copy of WinPE, MS-DART may be a great option. The link below brings you to a 30-day Evaluation download page.

For information about obtaining WinPE visit http://www.microsoft.com/licensing/sa/default.mspx

For information about obtaining the MS-DART 5.0 product, visit http://www.microsoft.com/downloads/details.aspx?familyid=5D600369-0554-4595-8AB4-C34B2860E087&displaylang=en

Once booted into WinPE or MS-DART 5.0, open a command prompt and run Diskpart.

You’ll notice that Diskpart isn’t fooled, it sees the disk size as we intend it to be, 130gb.

Now we select Disk 0 and then bring up the disk detail. (The Disk number may change obviously based on the disk you’re wanting to extend.)

We see here that the actual volume size is smaller, only 127gb. Now we have to select the Volume we want. Volume 1 in this example.

Now we extend the volume to encompass the newly added free space

Just to make sure – we look…

And we’re good to go! Simply reboot to the OS and enjoy the newly added disk space.

Sean Dwyer
Senior Support Engineer
Microsoft Enterprise Platforms Support

Exchanging files between Parent and Child Partitions in Hyper-V

jeffhugh — Tue, 16 Sep 2008 14:50:59 GMT

One of the most common questions asked about using Hyper-V is, "How can I access files on the Parent partition from inside the Child Partition?". In other Microsoft virtualization products like Virtual PC and Virtual Server 2005, this was possible, but even then, it was not accomplished in exactly the same way. In Virtual PC, a connection to a shared folder running on the physical host could be configured inside a virtual machine once the Virtual Machine Additions were installed. In Virtual Server 2005, this configuration could be accomplished using the Microsoft Loopback Adapter. In Hyper-V, the process is different. In Hyper-V, connectivity to the Parent partition from the Child partition can be accomplished by configuring an Internal virtual network using the Hyper-V Virtual Network Manager located in the Hyper-V Management interface (Figure - 1).

Figure - 1

Once the Internal virtual network is configured in the Hyper-V Management interface, a new Local Area Connection is made available in the Parent partition. This Local Area connection can be seen in the Network Connection interface (Figure -2).

Figure - 2

The next step is to configure the Child partition so it can use the newly configured Internal virtual network. This is accomplished in the settings for the Child partition by adding a new Network Adapter and mapping it to the Internal virtual network (Figure - 3) .

Figure - 3

Once this is completed, it is just a matter of configuring the Local Area Connection in the Parent and the new network interface in the Child to be on the same network (Figure - 4).

Figure - 4

A quick 'ping' test is be used to verify connectivity (Figure - 5)

Figure -5

Chuck Timon
Senior Support Escalation Engineer
Microsoft Enterprise Platforms Support

Cluster Resource Type options for Hyper-V

tomac — Wed, 27 Aug 2008 22:39:25 GMT

Windows Server 2008 Clustering includes resource type specific options which are available by right clicking on the group under Applications and Services.

For Hyper-V, we have the following options.

Manage virtual machine. This option opens Hyper-V Manager with connections to all participating nodes in the cluster. **NOTE: The virtual machine configuration resource must be online for the VM to be registered with Hyper-V and viewable in Hyper-V Manager.
Refresh virtual machine configuration. This option is the most important and is the primary focus of this blog.

In order to better explain how the Refresh virtual machine configuration option is important, let’s run thru a quick breakdown of how Windows Server 2008 Clustering stores information about each virtual machine.

Once you make a virtual machine highly available, we create two resources per VM excluding any disk resource(s).

Virtual machine configuration: This resource is responsible for registering/unregistering the virtual machine with Hyper-V on each node.

Virtual machine: This resource is responsible for changing the state of the VM. IE: Turn on, turn off, shutdown.

The VM resource that we want to inspect is the virtual machine configuration resource. In the screenshot below, I have used cluster.exe to dump the private properties for the “Virtual Machine Configuration HA VM” resource using the following syntax:

Cluster res “Virtual Machine Configuration HA VM” /priv

Note that we store the following in private properties.

VmSwitchPorts: This references the GUID and friendly name for the virtual network(s) the VM’s adapters are connected to as well as any VLAN ID defined for the virtual adapter(s) in the VM. In the example above, my Virtual Network is identified by Switch=’External’.

VmPhysicalDisks: If the virtual machine is configured to use a physical disk as a pass-through disk, the name of the Cluster Disk resource used as the pass-through disk will be referenced here. In the example above, my pass-through disk is identified as Resource=’Cluster Disk’.

VmID: This represents the VM GUID for the Virtual Machine. This is dynamically generated when the virtual machine is created and will not change.

VMStoreRootPath: This is the root folder location of the virtual machines directory for the VM, where our configuration data is stored.

The private properties only contain information that was passed to the Cluster service when the resource was created. So what if networking or disk information changes?

This is where the Refresh virtual machine configuration option comes into play. Whenever you need to make changes to the virtual network, such as connecting a VM Adapter to another virtual network, defining a VLAN ID, or changing the VLAN ID, you must refresh the virtual machine configuration in order for the VM Resource to come online. Also, if you decide to add a physical disk to the VM or replace a physical disk, you must refresh the virtual machine configuration in the cluster.

After right clicking on the group and selecting the option to “Refresh virtual machine configuration”, you will be prompted to take the virtual machine resource offline if it is not already. Once complete, you will be provided with a report similar to the Validation wizard with the outcome of the refresh operation.

The following screenshots provide an example of the report output. In this example, no changes are made. It is important to review the output incase other configuration changes are required.

Author:
Rob Hefner
Support Escalation Engineer
Microsoft Corporation

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