- A
The memory limit is automatically increased to 600Mi
Why wrong: Limits are not auto-adjusted; they must be changed in the YAML.
- B
The container is killed by the OOM killer, and the Pod enters CrashLoopBackOff
Exceeding the memory limit triggers OOM kill; the container restarts and may crash again.
- C
The Pod is evicted from the node
Why wrong: Eviction happens when the node is under resource pressure, not directly due to a single container exceeding its limit.
- D
The container is allowed to use up to 600Mi because the limit is a soft constraint
Why wrong: Limits are hard constraints; exceeding them causes termination.
Question 80 of 997
What Happens When a Container Exceeds Its Memory Limit in Kubernetes
This KCNA practice question tests your understanding of kubernetes fundamentals. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
You have a Pod with a container that runs a web server. The Pod has a memory request of 256Mi and a memory limit of 512Mi. The container attempts to allocate 600Mi of memory. What happens?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The container is killed by the OOM killer, and the Pod enters CrashLoopBackOff
When a container's memory usage exceeds its memory limit (512Mi), the Linux Out-Of-Memory (OOM) killer terminates the container process. Kubernetes then restarts the container based on the Pod's restart policy, but because the container immediately tries to allocate 600Mi again, it is repeatedly killed, resulting in a CrashLoopBackOff state. Memory limits are hard constraints enforced by the kernel via cgroups, not soft limits.
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 memory limit is automatically increased to 600Mi
Why it's wrong here
Limits are not auto-adjusted; they must be changed in the YAML.
- ✓
The container is killed by the OOM killer, and the Pod enters CrashLoopBackOff
Why this is correct
Exceeding the memory limit triggers OOM kill; the container restarts and may crash again.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The Pod is evicted from the node
Why it's wrong here
Eviction happens when the node is under resource pressure, not directly due to a single container exceeding its limit.
- ✗
The container is allowed to use up to 600Mi because the limit is a soft constraint
Why it's wrong here
Limits are hard constraints; exceeding them causes termination.
Common exam traps
Common exam trap: answer the scenario, not the keyword
A common misconception is that memory limits are 'soft' or 'advisory' (like CPU limits), but in Kubernetes, memory limits are hard and enforced by the kernel's OOM killer, causing container termination when exceeded.
Detailed technical explanation
How to think about this question
Under the hood, Kubernetes sets the container's memory limit as the `memory.limit_in_bytes` in the cgroup, and the Linux kernel tracks memory usage against this value. When the container's memory allocation (including anonymous pages, file cache, etc.) reaches the limit, the kernel invokes the OOM killer to reclaim memory by terminating the offending process. In a real-world scenario, this can happen even if the container's working set is below the limit but a transient spike causes a page allocation failure, leading to a seemingly sudden OOM kill.
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 KCNA 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.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Kubernetes Fundamentals — study guide chapter
Learn the concepts, then practise the questions
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FAQ
Questions learners often ask
What does this KCNA question test?
Kubernetes Fundamentals — This question tests Kubernetes Fundamentals — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The container is killed by the OOM killer, and the Pod enters CrashLoopBackOff — When a container's memory usage exceeds its memory limit (512Mi), the Linux Out-Of-Memory (OOM) killer terminates the container process. Kubernetes then restarts the container based on the Pod's restart policy, but because the container immediately tries to allocate 600Mi again, it is repeatedly killed, resulting in a CrashLoopBackOff state. Memory limits are hard constraints enforced by the kernel via cgroups, not soft limits.
What should I do if I get this KCNA 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 →
Same concept, more angles
1 more ways this is tested on KCNA
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 developer deploys a pod that continuously restarts. 'kubectl describe pod' shows the container exits with code 137. What is the most likely cause?
medium- ✓ A.The container is exceeding its memory limit and being OOM-killed.
- B.The liveness probe is failing and restarting the container.
- C.The init container is failing and blocking the main container.
- D.The pod is hitting a resource quota limit at the namespace level.
Why A: Exit code 137 (128 + 9) indicates the container was killed by SIGKILL. In Kubernetes, this most commonly occurs when the container exceeds its memory limit, triggering the OOM (Out-Of-Memory) killer. The kubelet enforces the resource limits specified in the pod spec, and when memory usage surpasses the limit, the kernel terminates the process with SIGKILL, resulting in exit code 137.
Keep practising
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- A pod in the 'production' namespace is in a CrashLoopBackOff state. The pod has been running successfully for several da…
- You need to ensure that a pod runs on a node with SSD storage. How can you achieve this?
- Match each Kubernetes resource to its primary purpose.
- Match each Kubernetes security concept to its definition.
- Which three of the following are valid methods to create or update resources in Kubernetes? (Choose three.)
Last reviewed: Jul 4, 2026
This KCNA 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 KCNA exam.
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