UNSOLVED Hyper-V Very Slow to Capture Image

  • My setup is a Microsoft 2016 server running Hyper-V Manager 10.0.14393.0. I have two VMs. One is a FOG server 1.5.5 running on Ubuntu 18.04.2 LTS. The other VM is my machine I create/update images (Windows 10) to the FOG server. I am noticing that when capturing an image it is very slow. For a 32GB image it takes between 7-8 hours. The only thing I found on the forums indicated that the Legacy Network Adapter used in the FOG virtual switch only runs at 100MB even when connected to a 1GB NIC. Is there a way to fix this or use an actual NIC instead of the virtual switch manager? Any information is greatly appreciated!

  • Senior Developer

    @bnorwood Sorry for my late reply…

    Please try the last command again exactly as I posted:

    ls -1 /sys/class/net/ | grep -v lo | xargs -n1 -I{} bash -c 'echo -n {} :" " ; basename `readlink -f /sys/class/net/{}/device/driver`'

    In the picture I see that the first quote before the echo a back tick was used instead of a single quote.

    Edit: I just saw the kernel version and I can imagine you still have one of the old kernels that had the Hyper-V slowness problem in it. Please update the kernel (FOG web UI -> FOG Configuration -> Kernel Update) and see if that makes a difference.

  • This is what I get.


  • Senior Developer

    @bnorwood Please start by scheduling a debug capture task. Boot the host and when you get to the shell run the following commands and post output here:

    uname -a
    ip a s
    ls -1 /sys/class/net/ | grep -v lo | xargs -n1 -I{} bash -c 'echo -n {} :" " ; basename `readlink -f /sys/class/net/{}/device/driver`'

    Note the backtick characters as well as single and double quotes. They all need to be used exactly as seen above.