Workload Cluster Upgrade stuck when upgrading from K8 version in PBD enabled environment

Products

• VMware Tanzu Kubernetes Grid

Issue/Introduction

Applications PODs are in crashloopback state.

Deleting the PODs doesn't not create new  PODs.

Environment

TKG 2.5.1

Cause

Since Nodepool upgrade gets stuck , NF pods get into CrashLoopBackoff status
PBD [ pod disruption budget] is enabled and the value of MaxUnavailable is 1. 

Resolution

1.Manually delete the problematic network function pods

2.Increase the MaxUnavailable of target PBD .