KB2905249 – "0x8007007A" Error When You Live Migrate A VM On WS2012 Or WS2012 R2 Hyper-V

I’ve done LOTS of live migrations since the beta of WS2012 and through WS2012 R2, and I’ve put the hosts under significant pressure. I can’t say I’ve seen the issue that is discussed & fixed in this new article by Microsoft where a "0x8007007A" error occurs when you migrate a virtual machine that’s running on Windows Server 2012 R2 Hyper-V or Windows Server 2012 Hyper-V.


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 (“The Update” via Windows Update). To resolve this issue in Windows Server 2012, install the Microsoft supplied hotfix.

One thought on “KB2905249 – "0x8007007A" Error When You Live Migrate A VM On WS2012 Or WS2012 R2 Hyper-V”

  1. Hi Aidan,

    I’ve run into this one a few times, but it was rare and it was very, very hard to reproduce. Feedback from MSFT confirmed it did exists in R2 as well (the fix was out longer for W2K12). It’s great to see that all bugs, frequent or not are being ironed out.

    Take care,


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.