[BUG] Node Auto-Provisioning: Unable to create node with Fsv2 SKU

[yoba730]

Describe the bug
When using Node Auto-Provisioning (NAP) on a new AKS cluster in Sweden Central, specifying sku-name: Standard_F4s_v2 in the NodePool requirements results in a warning and no node being created. However, removing sku-name (keeping only sku-family: F) works fine, and specifying another SKU like Standard_F2als_v6 also works. This suggests that Fsv2 SKUs might not be supported by NAP, even though they are available in the region and documented as examples.

To Reproduce
Steps to reproduce the behavior:

1. Create an AKS cluster in Sweden Central with Node Auto-Provisioning enabled.

2. Apply the following AKSNodeClass:

apiVersion: karpenter.azure.com/v1beta1
kind: AKSNodeClass
metadatametadata:
  name: test
spec:
  osDiskSizeGB: 30 

3. Apply the following NodePool:

apiVersion: karpenter.sh/v1
kind: NodePool
metadata:
  name: test
spec:
  disruption:
    consolidationPolicy: WhenEmptyOrUnderutilized
    consolidateAfter: 1m
  limits:
    cpu: "960"
  template:
    spec:
      expireAfter: 720h
      nodeClassRef:
        group: karpenter.azure.com
        kind: AKSNodeClass
        name: test
      requirements:
      - key: kubernetes.io/arch
        operator: In
        values: [amd64]
      - key: kubernetes.io/os
        operator: In
        values: [linux]
      - key: karpenter.sh/capacity-type
        operator: In
        values: [on-demand]
      - key: karpenter.azure.com/sku-family
        operator: In
        values: [F]
      - key: karpenter.azure.com/sku-name
        operator: In
        values: [Standard_F4s_v2]

4. Deploy a workload and observe the warning:
   Warning NoCompatibleInstanceTypes nodepool/test NodePool requirements filtered out all compatible available instance types

Expected behavior
The NodePool should successfully provision a node with the specified SKU (Standard_F4s_v2) since this SKU is available in Sweden Central and documented as an example for NAP.

Environment:

• Region: Sweden Central

• Kubernetes version: 1.32.0

• AKS Node Auto-Provisioning enabled

Additional context

• Removing sku-name works (node created with Standard_F2als_v6).

• Specifying Standard_F2als_v6 explicitly also works.

• Verified that Standard_F4s_v2 is available in Sweden Central by manually creating a node with this SKU.

• Documentation includes Standard_F4s_v2 as an example: NAP NodePool SKU examples.

Questions:

• Are Fsv2 SKUs currently unsupported by NAP?

• Is there a list of supported SKUs for NAP?

• Will Fsv2 SKUs be supported in the future? We rely on these machine types for our workloads.

[yoba730]

Hello,

I wanted to provide an update regarding the issue I reported earlier about FSv2 VM sizes not being available in AKS for the Node Auto-Provisioning (NAP). Initially, I observed that FSv2 sizes were not listed, and I did not make any changes to the cluster configuration. I simply left the cluster running before the holidays.

Upon returning, I noticed that FSv2 sizes are now available in the node claim, and I even have a node running on Standard_F2s_v2. This change occurred without any intervention on my side.

After reviewing Microsoft documentation, I learned that FSv2 series will be retired by November 2028. This might explain why these sizes were temporarily unavailable earlier, possibly due to quota adjustments or regional availability updates.

Thank you.

[sabbour]

Thanks for reporting back. Yes, there was a regression where retiring SKUs were not visible for Node Auto Provisioning. This has since been resolved at the data source. We do recommend opting for more modern SKUs as we may implement some weighing in the future to de prioritize SKUs that are being retired.