Hyper-V is killing my Epyc Rome system!

Jeff Robertson

Active Member
Oct 18, 2016
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Chico, CA
This is a fun one. I am attempting to run 2019 Hyper-v on a Supermicro H11 board with a 7402p CPU and am having no luck. After installing the hyper-v role the machine starts to boot loop. It looks like this is a fairly common issue as MS released a patch for the same behavior but I haven't been able to find a solution so far. Any ideas?
 

mbosma

Member
Dec 4, 2018
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Is AMD-Vi enabled?
I have had some issues installing hyper-v with Intels VT-d enabled which resulted in a boot loop.
The solution was to disabled VT-d in bios, maybe disabling AMD-Vi helps too.
 

Jeff Robertson

Active Member
Oct 18, 2016
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Chico, CA
Well this one has been fixed. I had an ISO from mid 19. I downloaded a "newer" version of the ISO from Microsoft and it worked. No idea what changed but something did.
 

weust

Active Member
Aug 15, 2014
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Almost sounds like you didn't run Windows Updates to get it to build 1909 (forgot is that applies to 2016 too).
 

Patrick

Administrator
Staff member
Dec 21, 2010
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Fun factoid. In August 2019 when Rome was released the Windows scheduler could not handle the 2x 128 thread CPUs. We needed a patched scheduler for that in the early days.
 

weust

Active Member
Aug 15, 2014
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It can't handle anything above 64 (iirc) cores properly, even in 2016/2019, without thrashing you event logs with a certain message.
Some 32bit old thing iirc. Damn annoying when you administer Hyper-V clusters with nodes that have 72 logical cores of which Hyper-V (at least 2012 does) only uses 64. So silly.
 
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i386

Well-Known Member
Mar 18, 2016
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Germany
Fun factoid. In August 2019 when Rome was released the Windows scheduler could not handle the 2x 128 thread CPUs. We needed a patched scheduler for that in the early days.
Did you encounter similar problems with other os (linux, bsd,esxi)?
 

MBerthe

New Member
Feb 28, 2019
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France
Hi,
I have the same trouble on another kind of hardware.
After long searches, I found that Windows 2019 can enter in a boot loop after Hyper-V installation.
The solution is to install at least January 22, 2019 cumulative update - KB4476976 (OS Build 17763.292).
If you are in the loop, start in recovery mode with Cmd and disable Hyper_V with
bcdedit /set hypervisorlaunchtype Off
Install the last cumulative update
Reboot
bcdedit /set hypervisorlaunchtype Auto
Reboot
And the server will boot like a charm!
Have a nice day