The correct answer is that the node is marked as unschedulable, but existing pods continue to run. This happens because the `kubectl cordon` command sets the `node.Spec.Unschedulable` field to true, which instructs the Kubernetes scheduler to ignore that node when placing new workloads. However, the kubelet on the cordoned node remains active, so any pods already running there are unaffected and will continue to operate normally until they are deleted or evicted by other means. On the CKA exam, this concept tests your understanding of node lifecycle management and the distinction between cordoning and draining—a common trap is confusing `cordon` with `drain`, which actually evicts pods. Remember the memory tip: “Cordon closes the door, but doesn’t kick anyone out.”
CKA Practice Question: Cluster Architecture, Installation and Configuration
This CKA practice question tests your understanding of cluster architecture, installation and configuration. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A node in the cluster has been cordoned. Which of the following is true about the node?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The node is marked as unschedulable, but existing pods continue to run.
When a node is cordoned using `kubectl cordon`, it is marked as unschedulable by setting the `node.Spec.Unschedulable` field to true. This prevents new pods from being scheduled onto the node, but existing pods continue to run normally. The node remains part of the cluster and is not removed or drained automatically.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The node is removed from the cluster.
Why it's wrong here
Cordoning does not remove the node; it only prevents scheduling.
✗
kubectl drain is automatically performed on the node.
Why it's wrong here
Drain is a separate operation that evicts pods; cordon does not trigger drain.
✓
The node is marked as unschedulable, but existing pods continue to run.
Why this is correct
Cordoning sets the node status to unschedulable, so no new pods are placed, but existing pods remain.
Related concept
Read the scenario before looking for a memorised answer.
✗
Existing pods on the node are immediately evicted.
Why it's wrong here
Cordoning does not evict existing pods; it only prevents new pods from being scheduled.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse cordoning with draining, assuming cordoning also evicts existing pods or removes the node, when in fact it only prevents new scheduling and leaves running pods untouched.
Detailed technical explanation
How to think about this question
Under the hood, `kubectl cordon` patches the node object to set `spec.unschedulable: true`, which the kube-scheduler reads and skips the node during pod placement. A real-world scenario is performing a node reboot: you cordon the node first to stop new pods, then drain it to evict existing pods gracefully, ensuring zero downtime for workloads.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the CKA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CKA question in full detail.
Cluster Architecture, Installation and Configuration — This question tests Cluster Architecture, Installation and Configuration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The node is marked as unschedulable, but existing pods continue to run. — When a node is cordoned using `kubectl cordon`, it is marked as unschedulable by setting the `node.Spec.Unschedulable` field to true. This prevents new pods from being scheduled onto the node, but existing pods continue to run normally. The node remains part of the cluster and is not removed or drained automatically.
What should I do if I get this CKA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A node has been cordoned. Which statement about the node is true?
medium
A.All pods on the node are immediately terminated
B.The kubelet on the node is stopped
C.The node is removed from the cluster
✓ D.The node is marked as unschedulable, but existing pods continue to run
Why D: When a node is cordoned using `kubectl cordon <node>`, it is marked as unschedulable by setting the `spec.unschedulable` field to `true`. This prevents new pods from being scheduled onto the node, but existing pods continue to run normally. The kubelet remains active, and the node stays in the cluster.
Last reviewed: Jun 24, 2026
Question Discussion
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This CKA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CKA exam.
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