VKS cluster scale-up not completed due to insufficient CPU resource

Products

• VMware vSphere Kubernetes Service

Issue/Introduction

1.VKS cluster scale up pending to wait for new machine become available:

Message:  Minimum availablility requires 3 replicats, current 2 avaiable
Reason:   WaitingForAvailableMachines

2. In vSphere client, below error show  that the new node keep trying to power on but failed due to insufficient CPU resource:

the amount of cpu resource available in the parent resource pool is insufficient for the operations

3.CPU is set unlimited already in the cluster namespace.

 

Environment

VMware vSphere Kubernetes Service

Cause

1.Check the actual available resource for the whole VKS cluster:

1）Open vSphere UI and click 'Namespaces' in left cluster panel

2）Click 'Monitor' -> CPU under Resource Allocation in right panel

3）You can find the available reservation for VKS namespaces

2.VKS cluster scale up with the guaranteed-large VM class, which requires 100% CPU to be reserved

3.It is confirmed that the available CPU resources in the whole namespaces cannot meet the CPU reservation requirements of the virtual machine,which is why the virtual machine cannot boot.

Resolution

1. Add more hosts or CPU resources to the current VKS cluster to increase available physical resources.

2. Deploy the VKS cluster using the best effort or a guaranteed VM class with less CPU reserved to ensure current resource availability.