Azure nodes in a VMSS node pool start but do not enter the Ready state

Hello @Eyal Gonen

The AKS node pool is failing to scale up despite an increased quota, resulting in pods stuck in a Pending state. The issue likely stems from a persistent quota problem, incorrect virtual network configuration, or other constraints preventing the nodes from becoming ready.

Reason 1: Quota Issues: Even though you increased the quota, it's possible the quota increase hasn't fully propagated across all Azure regions or resource providers. It's also possible that another resource is consuming the quota you expect to be available.

Reason 2: Virtual Network and Subnet Configuration: The AKS cluster's virtual network and subnet might not be configured correctly to allow the new nodes to join. This could include insufficient IP addresses in the subnet, Network Security Group (NSG) rules blocking necessary traffic, or User Defined Routes (UDRs) misdirecting traffic.

Reason 3: AKS Configuration Issues: There might be configuration issues within the AKS cluster itself, such as incorrect node pool settings, taints or labels preventing pod scheduling, or problems with the AKS control plane.

Reason 4: Azure Policy Constraints: Azure Policies applied to the subscription or resource group could be preventing the creation of the nodes. These policies might restrict the types of VMs that can be deployed, the regions where they can be deployed, or other aspects of the deployment.

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