The answer is to enable encryption at rest when creating the RDS instance using an AWS KMS key. This is correct because Amazon RDS for MySQL integrates with AWS Key Management Service to transparently encrypt the underlying storage, automated backups, read replicas, and snapshots, but crucially, encryption must be enabled at instance creation time—it cannot be added to an existing unencrypted instance. On the AWS Certified Database Specialty DBS-C01 exam, this concept tests your understanding of RDS encryption limitations and the principle that security configurations like encryption at rest are immutable post-launch. A common trap is assuming you can later modify an unencrypted DB instance to add encryption, which is not supported; instead, you must migrate data to a new encrypted instance. Remember the mnemonic: “Create to Encrypt, or you’ll decrypt your options.”
DBS-C01 Deployment and Migration Practice Question
This DBS-C01 practice question tests your understanding of deployment and migration. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 deploying a new Amazon RDS for MySQL database. The security team requires that all data at rest be encrypted. What is the simplest way to meet this requirement?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable encryption at rest when creating the RDS instance using an AWS KMS key
Amazon RDS for MySQL supports encryption at rest using AWS KMS keys, which must be enabled at instance creation time because encryption cannot be added to an existing unencrypted RDS instance. Option C is correct because it describes the simplest and most direct method: enabling encryption at rest during the initial RDS instance creation with an AWS KMS key, which transparently encrypts the underlying storage, automated backups, read replicas, and snapshots.
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.
✗
Enable encryption using AWS Certificate Manager
Why it's wrong here
ACM is for SSL/TLS certificates, not encryption at rest.
✗
Use client-side encryption in the application
Why it's wrong here
Client-side encryption is more complex and not the simplest way.
✓
Enable encryption at rest when creating the RDS instance using an AWS KMS key
Why this is correct
Encryption at rest can be enabled at instance creation time using a KMS key.
Related concept
Read the scenario before looking for a memorised answer.
✗
Enable encryption at rest on the RDS instance after creation
Why it's wrong here
Encryption cannot be enabled on an existing RDS instance; it must be done at creation.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may think encryption can be enabled after creation (Option D) because some AWS services allow post-creation encryption, but RDS requires encryption to be set at launch, and this is a common exam trick to test knowledge of RDS encryption limitations.
Detailed technical explanation
How to think about this question
When encryption at rest is enabled on an RDS instance, Amazon RDS uses AWS KMS to generate a data key that encrypts the storage volume using AES-256 encryption. This encryption is applied to the underlying EBS volumes, automated backups, and snapshots, and it is transparent to the database engine, meaning no application changes are required. A subtle behavior is that if you enable encryption at rest, you cannot disable it later, and you must specify the KMS key at creation time; also, encrypted read replicas must use the same KMS key or a different key in the same region.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
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.
Deployment and Migration — This question tests Deployment and Migration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Enable encryption at rest when creating the RDS instance using an AWS KMS key — Amazon RDS for MySQL supports encryption at rest using AWS KMS keys, which must be enabled at instance creation time because encryption cannot be added to an existing unencrypted RDS instance. Option C is correct because it describes the simplest and most direct method: enabling encryption at rest during the initial RDS instance creation with an AWS KMS key, which transparently encrypts the underlying storage, automated backups, read replicas, and snapshots.
What should I do if I get this DBS-C01 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
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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 is deploying a MySQL database on Amazon RDS and needs to enforce encryption at rest. Which configuration step is required?
medium
A.Use a custom DB parameter group with SSL enabled.
B.Modify the DB instance to enable encryption after creation.
C.Enable SSL/TLS on the RDS instance.
✓ D.Select encryption option when creating the RDS instance.
Why D: Option D is correct because enabling encryption at rest is done when launching the RDS instance. Option A is wrong because encryption is applied to the instance, not the engine. Option B is wrong because encryption is set at creation time. Option C is wrong because it's about encryption in transit, not at rest.
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This DBS-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 DBS-C01 exam.
Question Discussion
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