KB2894032 – Clustered VM Cannot Access Fiber Channel LUN After Performing Live Migration on WS2012 Hyper-V

FYI, Windows Server 2012 R2 allows VMs to have virtual fiber channel adapters that use the bandwidth of the hosts’ physical HBAs.  This means that VMs can have their own WWN (actually 2 WWNs per virtual HBA) and connect to zoned LUNs on an FC SAN.  This supports both Live Migration of those VMs, and the ability to use the FC LUNs as the shared storage of a guest cluster.

The first phase of Live Migration (that first 3% of the progress bar) is when Hyper-V attempts to build up a VM’s spec & dependencies on a destination host.  This includes connecting to any FC LUNs using the alternative WWN (hence 2 WWNs per virtual HBA).

Microsoft released a hotfix to deal with an issue on WS2012 Hyper-V where one of those FC enabled VMs loses connectivity to an FC LUN.


Consider the following scenarios:

  • You have two Windows Server 2012-based computers that have the Hyper-V role installed.
  • You install a virtual machine on one of the Windows Server 2012 Hyper-V hosts.
  • You set up a guest failover cluster, and then you make the virtual machine a cluster node.
  • The virtual machine is configured to access logical unit numbers (LUNs) over a Synthetic Fibre Channel.
  • You try to perform live migration to move the virtual machine to another Hyper-V host.

In this situation, the virtual machine on the target Hyper-V host cannot access the LUNs over the Synthetic Fibre Channel. 


This issue occurs because the target Hyper-V host cannot restore the Synthetic Fibre Channel LUN on behalf of the virtual machine during live migration.

More Information

You might receive the following error event and warning event when this issue occurs:

  • On the target Hyper-V host:

    Error event:
    Hyper-V SynthFC-Admin ID 32214 with description like
    Failed to reserve LUN with Instance Path ‘\?SCSI#VMLUN&Ven_HP&Prod_HSV360#5&17efa605&0&070002#{6f416619-9f29-42a5-b20b-37e219ca02b0}’ to virtual machine ‘WS2012-1’ with error: The data is invalid. (0x8007000D). (Virtual machine ID C799C113-B153-4E49-B0C5-F9E24774EB9A)
    Hyper-V SynthFC-Admin ID 32216 with description like
    Failed to register LUN with Instance Path ‘\?SCSI#VMLUN&Ven_DGC&Prod_RAID_5#5&378d83c&0&080200#{6f416619-9f29-42a5-b20b-37e219ca02b0}’ to virtual machine ‘SERVER2012R2-STD-64-1’ with error: The data is invalid. (0x8007000D). (Virtual machine ID 86FA60B1-8B40-45C5-A88F-1F024BECA8F0)

  • On the virtual machine:

    Warning Event:
    Microsoft-Windows-Ntfs ID 140
    The system failed to flush data to the transaction log. Corruption may occur in VolumeId: F:, DeviceName: DeviceHarddiskVolume82.
    (A device which does not exist was specified.)
    Event ID:50
    {Delaled Write Failed} Windows was unable to save all the data for the file. The data has been lost. This erorr may be caused by a failure of your computer hardware or network connection. Please try to save this file elsewhere.

A hotfix has been released to fix this problem.

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