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Bigbio2002
Asked: 2012-05-24 10:09:08 +0800 CST

How can I make my Hyper-V VMs properly save and restart when rebooting the host?

  • 772

My VMs are configured to save state, and restart if previously running when the host server is rebooted. All of the VMs start up upon reboot... however, some of them start from a cold boot, and not from a save state resume. Why is this occurring? I've searched for any relevant hotfixes, but I couldn't find any. The host is Server 2008 SP2 x64. I can't find a correlation between which guest VMs fail to properly resume, sometimes they do and sometimes they don't.

hyper-v

2 Answers

  1. Best Answer

    Why is this occurring?

    Your IO subsystem is too slow.

    Windows is not waiting forever for all the VM's to shut down. Once the timeout is over, it restarts.

    The only things helping are:

    • Change the timeout - no idea how ;)

    • Restart after patches via script. Save them BEFORE you restart.

    • Wait for 2012. Serve 2012 supposedly is a LOT better in this, including the ability to MOVE machines OFF a rebooting server so they stay online.

    • Get faster discs, so it takes less time.

    Sorry ;)

    Running 4 Hyper-V servers here and - well ;) Same problem. Got better since my main one was upgraded to 8 discs + 2 SSD for the VHD files ;)

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  2. check the event logs of the VM guests that started from a cold boot to see if they "unexpectedly rebooted" or crashed.

    also, double-check the settings for your VM's. there are three possible automatic stop options:

    • Save the virtual machine state (i.e., pause)
    • Turn off the virtual machine (i.e., stop without gracefully shutting down the guest)
    • Shut down the guest operating system (i.e., tell the guest OS to do a graceful shutdown)

    you might be confused by the shortened version of the last 2, which are "Save" and "Shut down".

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