Hyper-V host connectivity lost but VMs still communicate
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I just rebooted a CentOS 7 VM on the host and it lost network connectivity, cannot even ping the local gateway.
So it looks like networking is shitting itself, but online VMs are still working.
But it pulled a DHCP address...
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I bet if you rebooted the host the issue goes away (at least for a short while) what version drivers are installed for these NICs?
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@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
There is also the recommendation to disable "Enable Virtual Machine Queue" on both the host and the VM's to address this issue.
Always and forever disabled...
btw, I checked again just be to sure and it is still/back on when I swear I had turned it off at the Hyper-V level as well as in the settings for each VM over a year ago.
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@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
I bet if you rebooted the host the issue goes away (at least for a short while) what version drivers are installed for these NICs?
Of course it will as that is how I fixed it 3 weeks ago.
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@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
There is also the recommendation to disable "Enable Virtual Machine Queue" on both the host and the VM's to address this issue.
Always and forever disabled...
btw, I checked again just be to sure and it is still/back on when I swear I had turned it off at the Hyper-V level as well as in the settings for each VM over a year ago.
Just checked the VMs themselves. all disabled. cannot even comprehend how this is on and those are off.
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@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
There is also the recommendation to disable "Enable Virtual Machine Queue" on both the host and the VM's to address this issue.
Always and forever disabled...
Get-NetAdapterVmq | Disable-NetAdapterVmq
and everything starts running.
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According to my ScreenConnect timeline, the Hyper-V host lost connectivity just after midnight. There is not a damned thing in the logs for the time frame.
Up yours VMQ.....
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VQM to the rescue, am I right?
Maybe there is a bug in Hyper-V that enables it after a patch... I honestly don't know... just throwing darts...
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@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
VQM to the rescue, am I right?
Maybe there is a bug in Hyper-V that enables it after a patch... I honestly don't know... just throwing darts...
Quite possible because I patched the servers after November patch Tuesday and that first failure was the following week.
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Well I'm glad I was able to assist, make a note to check after patch tuesday to ensure VQM is off.
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@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
Well I'm glad I was able to assist, make a note to check after patch tuesday to ensure VQM is off.
Man, I don't wanna check each of these KB manually, but I guess I need to.
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Wouldn't it be easier to just check the host and VM's as you did previously, and saw it was enabled?
I mean, I get checking the patches... because there may be something in there that enables it again. I was thinking check monthly to ensure its still disabled after any new patches.
if its on again next month, then you could check the patches and see if something is enabling it.
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@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
Wouldn't it be easier to just check the host and VM's as you did previously, and saw it was enabled?
I mean, I get checking the patches... because there may be something in there that enables it again. I was thinking check monthly to ensure its still disabled after any new patches.
if its on again next month, then you could check the patches and see if something is enabling it.
For this, I meant to check if one of these patch was related to networking or VM config in some way.
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Execute the powershell script to disable VMQ at system boot?
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@JaredBusch oh I know, I was just thinking it may not be worth the 20 minutes to check the patches today.
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@dafyre said in Hyper-V host connectivity lost but VMs still communicate:
Execute the powershell script to disable VMQ at system boot?
wtf, you don't beat problems over the head with a sledge.
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@dafyre he could... but that isn't a fix to the issue, it's a bandaid.
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@DustinB3403 said in Hyper-V host connectivity lost but VMs still communicate:
@dafyre he could... but that isn't a fix to the issue, it's a bandaid.
It works until he finds the fix.
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@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@dafyre said in Hyper-V host connectivity lost but VMs still communicate:
Execute the powershell script to disable VMQ at system boot?
wtf, you don't beat problems over the head with a sledge.
Depends on the size of the problem.
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@dafyre said in Hyper-V host connectivity lost but VMs still communicate:
@JaredBusch said in Hyper-V host connectivity lost but VMs still communicate:
@dafyre said in Hyper-V host connectivity lost but VMs still communicate:
Execute the powershell script to disable VMQ at system boot?
wtf, you don't beat problems over the head with a sledge.
Depends on the size of the problem.
Sasquatch?