Upgrade kubernetes version from 1.20.x to 1.21.x

  • 25 August 2022
  • 3 replies

Hello ,


I have a kubernetes Cluster on Nutanix with 1 Master Node and 2 Worker Nodes(Test ENV). All the Nodes have Kubernetes version of 1.20.x. I want to Update the all the Nodes kubernetes version to 1.21.x. without the Downtime of application/services running on it. 


I have Seen in Nutanix guide which is easy step to upgrade kubernetes version but it says application may have downtime.


Any Ideas and Inputs to upgrade Kubernetes version from 1.20.x to 1.21.x withoutdown of apps.

3 replies

Userlevel 4
Badge +5

Hi Ashish,

You got the answer in the comments you left in the YouTube video.


With a single node control plane, the probability of having downtime is higher than with a three nodes control plane. While the single control plane node is being upgraded, new requests to the clusters won't be accepted and in the event of one of the worker nodes failing while upgrading this, the replicas running on that worker won't be restarted until the control plane is back.

Understood. I dont see an option to scale master node from prismcentra(karbon UI). Is it possible to add One more control plane for the existing Cluster??


Even after Having the cluster with 2 master Nodes and 2 worker nodes. When I click on upgrade kubernetes version to 1.21.x. (one Prism UI) How process works behind ??


  1. Does it upgrade master nodes paralelly or one after the other? same case for worker nodes ?
  2. Is there a way to monitor upgrade process ??



Yes, I understand. No option is available for scaling master nodes in prismcentra (karbon UI). Can we add one more control layer to the current Cluster??