VMs on OVH with Additional IP unable to be agile
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We have recently implemented shared storage for VMs and they are now agile, this works well.
We have xcp-ng hosted on OVH Cloud and have "Additional IPs" for various VMs to allow external access.
In OVH the additional IPs are associated with a server (xcp-ng host) so if an agile VM is moved to another host the additional IP no longer connects. The only solution I have found is to move the additional IP to the new host when the VM is migrated. This is possible however a more seamless solution would be better.
Is there a better way to manage VM migration when the VM has an additional IP?
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Hi,
IIRC, some hosting providers are blocking by default everything and only authorize the IPs/MAC when correctly moved on their panels (the same for Scaleway, OVH and few others).
That was the reasons we moved to our own machines/rack back in 2019. I suppose you can probably use a webhook or some automation to tell the provider API the IP is now on the new host, but even if you do, I think it takes few seconds to 1 minute to make it available again.
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Thank you. I never thought of using an automation. I'll look into that.
OVH does allow you to associate an additional IP with either a server or a vRack. We use vRack for the LAN so I think we can only associate the additional IP with the server.
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The problem with those providers is, that the additional IP is usually L3 routed to the physical hosts IP.
A better solution would be to get a /29 subnet or similar, where the gateway is handled by the provider and then configure that subnet on a specific VLAN which is available on all hosts where you want the VM's to be able to run.More work for the provider, since they have to setup the gateway IP within the /29 subnet on their router and then configure the VLAN on the switchports towards your hosts, but its the best way to make the VM's agile.
