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little-autumn-44758

09/21/2022, 5:18 PM
I've got a physical cluster with etcd/controlplane roles on some of the physical machines. I'd like to move these roles off to some VMs. What would be the proper steps to do this? Do I need to add the new VMs first, then remove the physical node(s)? Or the other way around?
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creamy-vr-37996

09/21/2022, 6:19 PM
AFAIK adding or removing masters from k8s is not an easy task to afford. Considering you´re moving from physicals to VMs, how about create a new controlplane on the virtual nodes, adding workers and perform a blue/green migration? Moving the core components of k8s should involve etcd data migration, controller and components along with losing both etcd/controlPlane quorum, not even talking about the certificates issues when you try to do something like move the components.
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quick-sandwich-76600

10/01/2022, 11:28 AM
@little-autumn-44758 To not have downtime nor risk of corruption is safe to do it in two stages. You can start adding 2 VMS to the etcd/control plane, so you have temporarily 5 nodes. Then remove 2 physical nodes, so you still have a quorum over one physical and two virtual. Finally, add the thrid VM, temporarily, you won't have a quorum, but, once the third VM is added to the cluster, you can just remove the last physical node.
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