5V0-23.20 VMware vSphere with Tanzu Specialist Questions and Answers

A ReplicaSet declares how the functionality of a pod is made scalable and resilient through redundancy. The ReplicaSet ensures that a specified number of pods is kept running. Example: Deploy a ReplicaSet. • The ReplicaSet name is nginx-replica-demo. • Two replicas are expected to be running. • The ReplicaSet applies to pods with label nginx.

For more information about Kubernetes replica sets, see https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/

The vSphere administrator defines and assigns VM storage policies to a namespace:

• VM storage policies are translated into Kubernetes storage classes.

• Developers can access all assigned VM storage policies in the form of storage classes.

• Developers cannot manage storage classes.

Developers can list the available storage classes in their namespace by running the kubectl describe ns command.

Virtual Machine Class Types for Tanzu Kubernetes Clusters

A virtual machine class defines the resource sizing for Tanzu Kubernetes cluster VMs: • CPU • Memory •

Storage

Virtual machine class types range from extra small (xsmall) to extra large (xlarge). Class types are categorized as guaranteed or best effort:

• Guaranteed: Reserve all CPU and memory allocations. • Best effort: Allocate the same CPU and memory but do not reserve the resources.

The class type guaranteed-small allocates 2 CPU, 4 GB of memory, and 16 GB of storage and reserves CPU and memory allocations. Custom virtual machine class types cannot be defined.

The Network Service has been extended to support the vSphere Distributed Switch (vDS). Start by configuring the switch with appropriate portgroups. Management will carry traffic between vCenter and the Kubernetes Control Plane (Supervisor Cluster control plane). As we will see in a moment, not having the built in Load Balancing capability of NSX means you will need to deploy your own load balancer externally from the cluster. We will give you a choice of integrated load balancers. The first one we support is HAProxy.

The Management network will also carry traffic between the supervisor cluster nodes and HAProxy. The Frontend network will carry traffic to the Load Balancer virtual interfaces. It must be routable from any device that will be a client for your cluster. Developers will use this to issue kubectl commands to the Supervisor cluster or their TKG clusters. You can have one or more Workload networks.

The primary Workload network will connect the cluster interfaces of the Supervisor cluster. Namespaces can be defined with their own Workload network allowing for isolation between development teams assigned different Namespaces. The Namespace assigned Workload Networks will connect the TKG cluster nodes in that Namespace.

Deleting Artifact:

When an artifact is not referenced by any OCI index, you can delete the artifact freely which will delete its manifest and all associated tags.

When an artifact is referenced by an OCI index, you cannot delete it. In order to delete this artifact, you must first delete all OCI indexes referencing this artifact first, remembering that an artifact can be referenced by multiple parents artifacts pushed onto Harbor by different users. So when deleting an OCI index holding 9 children artifacts not referenced by any other index and 1 child artifact referenced by another index, only 9 out of 10 children artifacts will be deleted.

To delete any artifact in the Harbor interface, click on the artifact and select ‘Delete’ and confirm.

Not Purge:As a vSphere administrator, you can purge the images for a project in the private image registry by request from DevOps engineers. Purging images from the private image registry deletes all references to the images made by pods, but it does not remove the images from the image registry.

Be aware of the following constraints when upgrading your cluster.

• You can upgrade a cluster up to one minor version of Kubernetes from its current version. If necessary, you can perform subsequent upgrades to move the version forward.
• Upgrading your version of Kubernetes is a one-way operation. You cannot subsequently downgrade the Kubernetes version, or undo an upgrade.

Tanzu Kubernetes Cluster is a Kubernetes cluster deployed by developers using a YAML specification file. It uses resources from hosts across vSphere clusters to form a Kubernetes cluster on vSphere. It also enables vSphere High Availability and Distributed Resource Scheduler, which allows for load balancing and high availability of resources in the cluster. It does not remove the Kubernetes API for use by DevOps teams.