Dear all,
I've been using ovirt for at least 6 years and only lately I've stepped into a weird problem that I hope someone will be able to give help.

My hardware is:
- blade lenovo for hosts, with dual switch
- dell equallogic for iscsi storage, directly connected to the blade switches
- The two host network cards are configured with bonding and all the vlans are accessed from it (mtu 9000)
- all the hosts and ovirt engine have firewalld service disabled)

My engine is hosted on a separate vmware vm (I will evaluate the self hosted engine later...). I want to stress the fact that for years this setup worked smoothly without any significant issue (and all the minor updates were completed flawlessly).

A few weeks ago I started the update from the rock solid 4.3 to the latest 4.4.7. I began with the manager, following the docs, installing a new centos8 vm and importing the backup: everything went smootly and I was able to get access to the manager without any problem, all the machines still there :)
I then began updating the hosts, from centos7 to centos8 stream, one by one.
Immediately I noticed network issues, with the VMs hosted on the first updated host. Migrating VMs from centos8 host to other centos8 quite often fails, but the main issue is this: if I start one of the VMs on the centos8 host, they have no network connectivity. If I migrate them to a centos7 hosts the network starts to work, and if I migrate the VMs back to the centos8 host, the network keeps working.
I am puzzled and can't understand what's going on. Generally speaking all the centos8 hosts (I have 6 in my cluster, and now 3 are centos8 while the rest is still centos7) seem to be very unstable, meaning that the VMs they host are quite often showing network issues and temporary glitches.

Can someone give a hint on how to solve this weird issue?


Thanks,
Andrea


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Andrea Chierici - INFN-CNAF 			
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