AKS how to delete old node pool system

Question

I created a new system node pool. I want to delete the old node pool. If I delete the old node pool, will the original service be extended to the new node pool's Pods？

Answer 1

You will need to drain the nodes before deleting the old node pool. Pods which are running on these nodes will be moved to New node pool, while you do so.
You may follow the below procedure for each nodes. AKS requires you to assign your new pool as the system pool manually, before deleting the old one

1. Get each node's full name- kubectl get nodes
2. Delete one by one- kubectl drain node-name --delete-local-data --ignore-daemonsets
3. Assign the new pool as a system pool: az aks nodepool update -g <RG Name> --cluster-name <Cluster Name> -n <short name of the node pool> --mode system

Reference here: use-system-pools

Answer 2

Just in case here is a link to official documentation - Resize node pools in Azure Kubernetes Service (AKS), if you need a bit more details in addition to @Manu Philip 's answer.