According to another post in the mailing list, the Engine Hosts (that has ovirt-ha-agent/ovirt-ha-broker running) is checking http://{fqdn}/ovirt-engine/services/health

As the IP is changed, I think you need to check the URL before and after thr mifgration.

Best Regards,
Strahil NikolovOn Jul 23, 2019 16:41, Derek Atkins <derek@ihtfp.com> wrote:
>
> Hi,
>
> If I understand it correctly, the HE Hosts try to ping (or SSH, or
> otherwise reach) the Engine host.  If it reaches it, then it passes the
> liveness check. If it cannot reach it, then it fails.  So to me this error
> means that there is some configuration, somewhere, that is trying to reach
> the engine on the old address (which fails when the engine has the new
> address).
>
> I do not know where in the *host* configuration this data lives, so I
> cannot suggest where you need to change it.
>
> Can 10.16.248.x reach 10.8.236.x and vice-versa?
>
> Maybe multi-home the engine on both networks for now until you figure it out?
>
> -derek
>
> On Tue, July 23, 2019 9:13 am, carl langlois wrote:
> > Hi,
> >
> > We have managed to stabilize the DNS udpate in out network. Now the
> > current
> > situation is.
> > I have 3 hosts that can run the engine (hosted-engine).
> > They were all in the 10.8.236.x. Now i have moved one of them in the
> > 10.16.248.x.
> >
> > If i boot the engine on one of the host that is in the 10.8.236.x the
> > engine is going up with status "good". I can access the engine UI. I can
> > see all my hosts even the one in the 10.16.248.x network.
> >
> > But if i boot the engine on the hosted-engine host that was switch to the
> > 10.16.248.x the engine is booting. I can ssh to it but the status is
> > always
> > " fail for liveliness check".
> > The main difference is that when i boot on the host that is in the
> > 10.16.248.x network the engine gets a address in the 248.x network.
> >
> > On the engine i have this in the
> > /var/log/ovirt-engine-dwh/ovirt-engine-dwhd.log
> > 019-07-23
> > 09:05:30|MFzehi|YYTDiS|jTq2w8|OVIRT_ENGINE_DWH|SampleTimeKeepingJob|Default|5|tWarn|tWarn_1|Can
> > not sample data, oVirt Engine is not updating the statistics. Please check
> > your oVirt Engine status.|9704
> > the engine.log seems okey.
> >
> > So i need to understand what this " liveliness check" do(or try to do) so
> > i
> > can investigate why the engine status is not becoming good.
> >
> > The initial deployment was done in the 10.8.236.x network. Maybe is as
> > something to do with that.
> >
> > Thanks & Regards
> >
> > Carl
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Jul 18, 2019 at 8:53 AM Miguel Duarte de Mora Barroso <
> > mdbarroso@redhat.com> wrote:
> >
> >> On Thu, Jul 18, 2019 at 2:50 PM Miguel Duarte de Mora Barroso
> >> <mdbarroso@redhat.com> wrote:
> >> >
> >> > On Thu, Jul 18, 2019 at 1:57 PM carl langlois <crl.langlois@gmail.com>
> >> wrote:
> >> > >
> >> > > Hi Miguel,
> >> > >
> >> > > I have managed to change the config for the ovn-controler.
> >> > > with those commands
> >> > >  ovs-vsctl set Open_vSwitch . external-ids:ovn-remote=ssl:
> >> 10.16.248.74:6642
> >> > >  ovs-vsctl set Open_vSwitch . external-ids:ovn-encap-ip=10.16.248.65
> >> > > and restating the services
> >> >
> >> > Yes, that's what the script is supposed to do, check [0].
> >> >
> >> > Not sure why running vdsm-tool didn't work for you.
> >> >
> >> > >
> >> > > But even with this i still have the "fail for liveliness check" when
> >> starting the ovirt engine. But one thing  i notice with our new network
> >> is
> >> that the reverse DNS does not work(IP -> hostname). The forward is
> >> working
> >> fine. I am trying to see with our IT why it is not working.
> >> >
> >> > Do you guys use OVN? If not, you could disable the provider, install
> >> > the hosted-engine VM, then, if needed, re-add / re-activate it .
> >>
> >> I'm assuming it fails for the same reason you've stated initially  -
> >> i.e. ovn-controller is involved; if it is not, disregard this msg :)
> >> >
> >> > [0] -
> >> https://github.com/oVirt/ovirt-provider-ovn/blob/master/driver/scripts/setup_ovn_controller.sh#L24
> >> >
> >> > >
> >> > > Regards.
> >> > > Carl
> >>