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Microsoft Hyper-V Virutal Machine Bus Provider problem RRS feed

  • Question

  • Hello

    I have a two node Hyper-V Cluster built on two Windows 2012R2 hosts. Yesterday after major long power failure (cluster went down due power loss) we have tried to bring it up. On both hosts there is a problem with Microsoft Hyper-V Virutal Machine Bus Provider in Device Manager - it'a marked with yellow triangle with status: 'The driver for this device are not installed. (Code 28). Driver provider is unknown, driver date and version are not available.

    This is how it was before:

    Device ROOT\VMBUS\0000 was configured.

    Driver Name: wvmbusr.inf
    Class Guid: {4D36E97D-E325-11CE-BFC1-08002BE10318}
    Driver Date: 06/21/2006
    Driver Version: 6.3.9600.16384
    Driver Provider: Microsoft
    Driver Section: VMBus_Device_Root.NT
    Driver Rank: 0xFF0000
    Matching Device Id: root\VMBus
    Outranked Drivers: 
    Device Updated: true

    And this is how it looks now:

    Device ROOT\VMBUS\0000 was configured.

    Driver Name: null
    Class Guid: {00000000-0000-0000-0000-000000000000}
    Driver Date: 
    Driver Version: 
    Driver Provider: 
    Driver Section: 
    Driver Rank: 0x0
    Matching Device Id: 
    Outranked Drivers: 
    Device Updated: false

    Ive chcecked the drivers location for this device on my another cluster and it seems that on the failed cluster 3 files located in \Windows\system32\drivers went missing: vmbkmclr.sys, vmbusr.sys and winhvr.sys. Ive restored them but device is still not accesible.

    How can i fix this problem? 

    Saturday, July 23, 2016 12:38 PM

Answers

  • Hi J3drek79,

    Have you tried to right click on it and update driver?

    >>missing driviers for this device on both of my Hyper-V hosts is causing problem with starting all my virtual machines. 

    What problems?

    • Have you tried the steps in the following KB?
    https://support.microsoft.com/en-sg/kb/954282

    Best Regards,

    Leo


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    • Edited by Leo Han Monday, July 25, 2016 4:21 AM
    • Proposed as answer by Leo Han Tuesday, August 2, 2016 8:30 AM
    • Marked as answer by Leo Han Monday, August 8, 2016 4:36 AM
    Monday, July 25, 2016 4:20 AM

All replies

  • These Virtual Devices (VDev) are provided for Automatic Virtual Machine Activation (AVMA) to communicate with the host. AVMA is only supported on virtual machines running Windows Server 2012 R2 or later versions of operating systems.

    The unknown devices are harmless and can be ignored. 

    Hope it will help you.

    Mark as answer if it help you.

    Thanks

    Saturday, July 23, 2016 3:00 PM
  • It won't help me unfortunatly - missing driviers for this device on both of my Hyper-V hosts is causing problem with starting all my virtual machines. 
    Saturday, July 23, 2016 3:17 PM
  • Hi J3drek79,

    Have you tried to right click on it and update driver?

    >>missing driviers for this device on both of my Hyper-V hosts is causing problem with starting all my virtual machines. 

    What problems?

    • Have you tried the steps in the following KB?
    https://support.microsoft.com/en-sg/kb/954282

    Best Regards,

    Leo


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.


    • Edited by Leo Han Monday, July 25, 2016 4:21 AM
    • Proposed as answer by Leo Han Tuesday, August 2, 2016 8:30 AM
    • Marked as answer by Leo Han Monday, August 8, 2016 4:36 AM
    Monday, July 25, 2016 4:20 AM