EX280 Cluster Installation And Management Practice Test 3 — 15 Questions

Question 1

An administrator needs to perform an offline (disconnected) upgrade of an OpenShift 4.14 cluster where nodes have no direct internet access. Which resource must be configured in the cluster to supply the release payload images from a local mirror registry?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

ImageContentSourcePolicy (or ImageTagMirrorSet). In a disconnected environment, an ImageContentSourcePolicy (or ImageTagMirrorSet in newer versions) is configured to redirect image pull requests from official repositories to a local mirror registry.

Answer

ClusterVersion mirror override parameter

Answer

MachineConfig registry redirection file

Answer

OperatorGroup mirror setting

Question 2

An administrator wants to check why a specific MachineConfigPool is taking a long time to complete an update. Which status condition on the MachineConfigPool indicates that nodes are currently being updated?

Accepted Answer

Updating=True. The MachineConfigPool status includes conditions such as Updating, Updated, and Degraded. The 'Updating' condition indicates that nodes are actively applying the configuration.

Answer

RollingOut=Running

Answer

Reconciling=Pending

Answer

Progressing=Active

Question 3

Which namespace contains the Machine Config Operator (MCO) and its associated daemon pods in OpenShift 4.14?

Accepted Answer

openshift-machine-config-operator. The MCO runs in the openshift-machine-config-operator namespace.

Answer

openshift-infra

Answer

openshift-machine-api

Answer

openshift-cluster-version

Question 4

Which component in OpenShift 4.14 manages the creation and deletion of compute machines (VMs or physical servers) on cloud providers or bare metal?

Accepted Answer

Machine API Operator. The Machine API Operator manages the underlying compute infrastructure using Custom Resources such as Machines and MachineSets.

Answer

Operator Lifecycle Manager

Answer

Machine Config Operator

Answer

Cluster Version Operator

Question 5

An administrator wants to perform a manual rollback of a MachineConfig change that caused issues on worker nodes. What is the standard way to revert to the previous configuration using the Machine Config Operator?

Accepted Answer

Delete the problematic MachineConfig object, causing the MCO to automatically roll back nodes to the previous configuration.. To rollback a MachineConfig, the administrator can delete the erroneous MachineConfig object, and the MCO will automatically revert the nodes to the previous valid configuration.

Answer

Reboot each worker node into the previous GRUB menu entry manually via IPMI.

Answer

Run 'oc rollback machineconfigpool worker'.

Answer

Run 'oc adm node-rollback --pool=worker'.

Question 6

An administrator needs to verify that the cluster autoscaler is successfully scaling worker nodes in response to pending pods. Which custom resource should the administrator inspect to check the autoscaler configuration and status?

Accepted Answer

ClusterAutoscaler and MachineAutoscaler. Cluster scaling parameters and status are managed and viewed via the ClusterAutoscaler and MachineAutoscaler custom resources in OpenShift.

Answer

NodeScalingOperator resource

Answer

MachineConfigPool autoscaler status

Answer

ClusterVersion autoscaling spec

Question 7

An administrator needs to check the status of all MachineSets in an OpenShift 4.14 cluster to see how many worker machines are currently provisioned and running. Which command should be used?

Accepted Answer

oc get machinesets -A (or within openshift-machine-api). The 'oc get machinesets' command lists all MachineSets along with their desired, current, and ready replica counts.

Answer

oc adm get machines

Answer

oc get cluster-infrastructure

Answer

oc get machineconfigpools

Question 8

An administrator wants to temporarily disable a MachineHealthCheck so that node maintenance can be performed without triggering automated node deletion. How should this be done?

Accepted Answer

Delete the MachineHealthCheck custom resource during the maintenance window and recreate it afterward.. To disable a MachineHealthCheck, the administrator can scale its target remediation or delete the MachineHealthCheck resource, or annotate/pause it depending on implementation, but deleting or scaling spec (if supported) or deleting the MHC resource is standard practice during extended maintenance.

Answer

Set the MachineHealthCheck replica count to zero.

Answer

Stop the machine-api-operator deployment.

Answer

Annotate every node with 'machinehealthcheck.openshift.io/enabled=false'.

Question 9

An administrator wants to inspect the ignition configuration generated for worker nodes by the Machine Config Operator. Which command or resource should the administrator examine?

Accepted Answer

Inspect the rendered MachineConfig objects (e.g., rendered-worker-*) managed by the MCO.. Ignition configs are generated and stored inside ControllerConfigs or rendered MachineConfigs managed by the MCO.

Answer

Run 'oc adm inspect ignition-configs'.

Answer

Check the ConfigMap named 'ignition-worker' in the default namespace.

Answer

View the ClusterVersion status conditions.

Question 10

What is the primary function of a MachineSet in an OpenShift 4.14 cluster running on a cloud provider?

Accepted Answer

To ensure a specified number of identical machine instances are running and healthy.. A MachineSet ensures that a specified number of machine replicas are running, acting similarly to a ReplicaSet for pods but for compute machines.

Answer

To load balance ingress traffic across worker nodes.

Answer

To manage persistent volume claims across storage backends.

Answer

To group cluster nodes by operating system kernel version.

Question 11

An administrator has added a new custom worker MachineConfigPool and wants existing worker nodes to be migrated into this new pool based on specific labels. How does an administrator move a node from the default worker pool to a custom MachineConfigPool?

Accepted Answer

Apply the corresponding role label to the node (e.g., 'oc label node worker-01 node-role.kubernetes.io/custom-worker='').. To move a node to a custom MachineConfigPool, the administrator must label the node with the role label matching the custom MachineConfigPool (e.g., node-role.kubernetes.io/<pool-name>='').

Answer

Modify the cluster-wide node migration ConfigMap.

Answer

Edit the MachineSet to change its target pool name.

Answer

Run 'oc adm migrate node worker-01 --to-pool=custom-worker'.

Question 12

Which component in OpenShift 4.14 serves as the API entry point for managing MachineAPI resources like Machines and MachineSets?

Accepted Answer

Machine API Operator. The Machine API Operator provides the custom resource definitions and controllers for managing Machine and MachineSet objects.

Answer

Cluster Version Operator

Answer

Machine Config Operator

Answer

Operator Lifecycle Manager

Question 13

An administrator wants to verify if the OpenShift cluster upgrade to version 4.14 has successfully completed for all core components. Which status field in the ClusterVersion resource should show 'True' for the progressing and available conditions?

Accepted Answer

Available=True and Progressing=False. During a successful cluster upgrade, the 'Available' condition is True and the 'Progressing' condition becomes False once completed.

Answer

Completed=True and Ready=True

Answer

Available=False and Progressing=True

Answer

Upgraded=True and Finished=True

Question 14

An administrator is managing an OpenShift 4.14 cluster and notices that a newly installed Operator fails to start because it requires a specific version of Kubernetes that is older than what OpenShift 4.14 provides. How does OLM handle Operator compatibility checks during subscription creation?

Accepted Answer

OLM evaluates the ClusterServiceVersion (CSV) metadata against the cluster version and blocks installation if requirements are unmet.. OLM checks the 'minVersion' and 'maxVersion' or 'capabilities' specified in the Operator's CSV against the cluster version and will not install an incompatible CSV, keeping the installation pending or failing.

Answer

The kube-apiserver automatically patches the operator deployment to bypass version checks.

Answer

The operator runs inside a compatibility emulation container provided by the MCO.

Answer

The Cluster Version Operator automatically downgrades the cluster Kubernetes API to match the Operator.

Question 15

Which OpenShift 4.14 command allows an administrator to gather cluster-wide diagnostic logs and configuration data for support cases?

Accepted Answer

oc adm must-gather. The 'oc adm must-gather' tool collects debugging information, logs, and object definitions from the cluster into a local directory.

Answer

oc adm collect-logs

Answer

oc support dump

Answer

oc cluster-debug bundle