Question 1,482 of 1,733
Operations and MaintenancemediumMultiple ChoiceObjective-mapped

Patching EC2 Instances in Auto Scaling Groups

This PAS-C01 practice question tests your understanding of operations and maintenance. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 company is running SAP on AWS and wants to implement a patching strategy for the operating system of EC2 instances with minimal downtime. The instances are part of an Auto Scaling group. Which of the following approaches is the MOST appropriate?

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

Create a new Amazon Machine Image (AMI) with the latest patches, update the launch configuration, and perform a rolling update of the Auto Scaling group.

Option D is correct because creating a new AMI with the latest patches, updating the launch configuration, and performing a rolling update of the Auto Scaling group replaces instances with patched AMIs without downtime. Option A is incorrect because applying patches directly to running instances using AWS Systems Manager Patch Manager requires reboots, causing downtime for each instance. Option B is incorrect because stopping the Auto Scaling group stops all instances, resulting in full downtime. Option C is incorrect because using Patch Manager to patch all instances at the same time during a maintenance window would cause simultaneous reboots, leading to downtime.

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.

  • Apply patches directly to the running instances using AWS Systems Manager Patch Manager and reboot each instance one at a time.

    Why it's wrong here

    This approach still causes downtime for each instance as it reboots.

  • Stop the Auto Scaling group, patch the instances, and start the group again.

    Why it's wrong here

    Stopping the Auto Scaling group stops all instances, causing full downtime.

  • Use AWS Systems Manager Patch Manager to patch all instances at the same time during a maintenance window.

    Why it's wrong here

    Patching all instances simultaneously would cause all instances to reboot at the same time, resulting in downtime.

  • Create a new Amazon Machine Image (AMI) with the latest patches, update the launch configuration, and perform a rolling update of the Auto Scaling group.

    Why this is correct

    This approach replaces instances with patched ones without downtime as the Auto Scaling group launches new instances before terminating old ones.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.

Detailed technical explanation

How to think about this question

This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.

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.
  • Use explanations to understand the rule behind the answer.

TExam Day Tips

  • Underline the problem statement mentally.
  • 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 cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

What to study next

Got this wrong? Here's your next step.

Identify which PAS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

Related practice questions

Related PAS-C01 practice-question pages

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FAQ

Questions learners often ask

What does this PAS-C01 question test?

Operations and Maintenance — This question tests Operations and Maintenance — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Create a new Amazon Machine Image (AMI) with the latest patches, update the launch configuration, and perform a rolling update of the Auto Scaling group. — Option D is correct because creating a new AMI with the latest patches, updating the launch configuration, and performing a rolling update of the Auto Scaling group replaces instances with patched AMIs without downtime. Option A is incorrect because applying patches directly to running instances using AWS Systems Manager Patch Manager requires reboots, causing downtime for each instance. Option B is incorrect because stopping the Auto Scaling group stops all instances, resulting in full downtime. Option C is incorrect because using Patch Manager to patch all instances at the same time during a maintenance window would cause simultaneous reboots, leading to downtime.

What should I do if I get this PAS-C01 question wrong?

Identify which PAS-C01 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Same concept, more angles

1 more ways this is tested on PAS-C01

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 company runs SAP on AWS and needs to patch the operating system of multiple EC2 instances on a schedule. The instances are part of an Auto Scaling group. Which AWS service can be used to apply patches without disrupting the Auto Scaling group's desired capacity?

medium
  • A.AWS Systems Manager Patch Manager
  • B.Amazon EC2 Auto Scaling
  • C.AWS CloudFormation
  • D.AWS CodeDeploy

Why A: AWS Systems Manager Patch Manager can be used to apply OS patches to EC2 instances on a schedule. It integrates with Auto Scaling groups to maintain desired capacity, for example by using instance refresh to roll out patches without disrupting the group's capacity. Option B (Amazon EC2 Auto Scaling) is incorrect because it manages scaling, not patching. Option C (AWS CloudFormation) is incorrect because it is used for infrastructure provisioning, not patching. Option D (AWS CodeDeploy) is incorrect because it is for application deployments, not OS patching.

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Last reviewed: Jun 20, 2026

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This PAS-C01 practice question is part of Courseiva's free Amazon Web Services 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 PAS-C01 exam.