Issues with 7.6 and HyperV 16

We don’t know before someone has tried. Given the experience of the last weeks I speculate a 50/50 chance that it might work flawless with a new kernel version. I wouldn’t do it on a production system. If I need to update an NS package then I go with ssh into NS and yum install . That’s what I did while I was waiting for 4.2.8. And set a checkpoint so that I can recover it easily.

On my HyperV16 (2xNS and 1 Centos native VM) Kernel 3.10.0-957.5.1 works again with LIS (released 2/12/19)


Thanks for updating us

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found some time :grin: i’m not really an hyper-v expert but:
install minimal centos 7.5 and all is working as expected
do a full update, and network is still working without lis.
install ns76 from shell, ssh and webui OK. reboot
ssh and webui ok, finish wizard still ok.
install firewall base and set static ip and all still works.
so the problem seems to show up only when upgrading ns75 to ns76… i’ll do some other tests

According to my experience neither NS76 nor standard Centos76 run smoothly (even on fresh install) as guest VM under HyperV 16 if the LIS and Kernel versions are not in sync. The issues are usually with the networking stack. It looks to me that this is not a NS specific ssue.

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i didn’t have lot of c7 on hyperv, but i’ve made some other tests, and I didn’t have problem with
c7.5 -> c7.6
with simple c7 install and webserver on it.
as soon as i install ns76 on c76 (installed or upgraded) i lost network. it seem to work only if there is only one cpu and only one queue on eth0.
changing some config on eth0 like tx or number of combined queues make it works again (also changing back to original value)
i prefer to avoid to install LIS, the built-in version are more than enough for me

so for now i have added an ETHTOOL_OPTS to ifcfg-eth (ETHTOOL_OPTS="-G {DEVICE} rx 10486; -G {DEVICE} tx 192")
and it works.
i’m not sure it’s an ns76 problem, but,
i have no errors on centos 7.6, errors start installing ns76 and no rhel or centos errata/bug (or at least i didn’t find it)…


@dz00te could you please have a look at this issue?

More details about the implementation are in the PR:

I understand that the HyperV problems seem different, but maybe udev is triggered again and it puts down the network cards.

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thank you for the input i miss this issue… in effect, it seems that simply commenting the line in /etc/udev/rules.d/95-NetworksDB.rules make it work all again. I hope to have some time this afternoon to make some other tests and check the script. tnx

i’m sorry to not have some time to test properly… anyway, after the latest upgrade of nethserver-base it seems to work without any trick :+1:
i’ve also made an install of ns76 over a c76, i had to reboot to access, but honestly, i didn’t remeber if the vm i used was used for other tests,so i’ll retry with a clean install tomorrow

confirmed, installing ns76 from plain centos bring down the eth0, a simple reboot solve the problem

Bump up…
New kernel has been released by CentOS, 3.10.957.10.1.
Microsoft released 4.2.8-2 version of LIS on 04 of March
Consider if diligent the update before the kernel update of the guest…

Microsoft stated necessary LIS 4.2 for any 7.x version of CentOS.


NS with Kernel 3.10.957.10.1. and Microsoft LIS LIS 4.3 works fine as a guest in my HyperV Server 2016 set-up (Xeon E5-2618Lv4)

3 days ago LIS was updated to version 4.3.1-1
I don’t use this hypervisor, but my scapegoat server is updating to a new kernel, therefore… Maybe could help the Hyper-V-Fans…

(This thing is starting to get ridiculous…)

Tested it this morning on Hyper-V 2016

LIS 4.3.1.-1 can be upgraded in NS with Kernel 3.10.0-957.10.1.

LIS upgrade fails with latest Kernel 3.10.0-957.12.2 which is currently available in the NS software center.

Looks like LIS 4.3.1-1 is still behind in Kernel versioning.

LIS 4.3.2 upgrades under Kernel 3.10.0-957.12.2

lis-4.3.0.tar.gz -> 585 MB
lis-4.3.1-1.tar.gz -> 617 MB
lis-4.3.2-tar.gz -> 168 MB

O_o mysterious mistero…


Centos includes the necessary Hyper-V daemons by default - “from MS : LIS are included as part of this Linux distribution”.

A while ago I installed the Microsoft LIS services since my NS 7.6 did not work flawlessly under MS Hyper-V 2016 with the built-in LIS. In the meantime there had been a couple of Kernel updates and I was curious if the package MS LIS is still needed.

Yesterday I removed MS LIS 4.3.3 switching back to the Centos built-in LIS daemons. NS 7.6 is working stable (as a Generation 2 VM-Guest in Microsoft Hyper-V Server 2019). This is great news since it has been a pain to block kernel updates until a new MS LIS has been released.


According to this documentation, HyperV should support without any addon CentOS 7.6 and 7.9
Otherwise, consider to install LIS 4.3, currently updated during 2020.