"0x8007007A" error when you migrate a virtual machine that's running Windows Server 2012 R2 or Windows Server 2012

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 Datacenter


Consider the following scenario:
  • You have two Hyper-V hosts that are running Windows Server 2012 R2 or Windows Server 2012.
  • You use the Live Migration feature in Hyper-V to migrate a virtual machine from one server to another.

In this scenario, the migration fails. Additionally, a "0x8007007A" error that resembles the following is logged in the System log:

Log Name: System
Source : Microsoft-Windows-Hyper-V-High-Availability
Event ID: 21502
Level : Error
Message :Live migration of 'VM_Name' failed.Virtual machine migration operation for "VM_Name' failed at migration source 'Node_Name'. (Virtual machine ID VM_GUID) Failed to save the virtual machine partition state: The data area passed to a system call was too small. (0x8007007A). (Virtual machine ID VM_GUID)


To resolve this issue in Windows Server 2012 R2, install update 2919355.
To resolve this issue in Windows Server 2012, install the hotfix that is described in this article.

Update information for Windows Server 2012 R2

For more information about how to obtain update 2919355, click the following article number to view the article in the Microsoft Knowledge Base:
2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014

Hotfix information

A supported hotfix is available from Microsoft Support. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, go to the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must be running Windows Server 2012.

Restart requirement

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any previously released hotfix.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


See the terminology Microsoft uses to describe software updates for more information.