The answer is Amazon Simple Storage Service (S3). S3 is the correct choice because it is a cost-effective, highly scalable object store that provides native integration with both Amazon EMR and Redshift Spectrum, allowing them to read data directly without needing to move or copy it. In contrast, EBS volumes are tied to a single EC2 instance and cannot be shared across services, while EMRFS is simply the connector that lets EMR use S3, not a separate storage solution. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your understanding of shared data lake storage patterns, where S3 serves as the central repository for analytics services. A common trap is confusing EMRFS with a storage service—remember that EMRFS is just a filesystem adapter for S3. For a quick memory tip: think of S3 as the single source of truth for your data lake, accessible by any service without lock-in.
DEA-C01 Data Store Management Practice Question
This DEA-C01 practice question tests your understanding of data store management. 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 company is migrating an on-premises Hadoop cluster to AWS. The data is stored in HDFS and needs to be accessible by both Amazon EMR and Amazon Redshift Spectrum. Which storage solution is most cost-effective and scalable?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Amazon Simple Storage Service (S3)
Option B is correct because Amazon S3 is a cost-effective, scalable object store that can be accessed by both EMR and Redshift Spectrum. Option A is wrong because EBS is limited to a single EC2 instance. Option C is wrong because EFS is a file system, not as cost-effective for large-scale data. Option D is wrong because Amazon FSx for HDFS is designed for HDFS compatibility but is more expensive than S3.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Amazon FSx for HDFS
Why it's wrong here
FSx for HDFS is expensive compared to S3 and not necessary for this use case.
✓
Amazon Simple Storage Service (S3)
Why this is correct
S3 is highly scalable, durable, and can be queried by Redshift Spectrum and processed by EMR.
Related concept
Static NAT maps one inside address to one outside address.
✗
Amazon Elastic Block Store (EBS)
Why it's wrong here
EBS volumes are attached to a single instance and not cost-effective for large datasets.
✗
Amazon Elastic File System (EFS)
Why it's wrong here
EFS is a file system for Linux instances, not optimal for large-scale data lakes.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
Data Store Management — This question tests Data Store Management — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Amazon Simple Storage Service (S3) — Option B is correct because Amazon S3 is a cost-effective, scalable object store that can be accessed by both EMR and Redshift Spectrum. Option A is wrong because EBS is limited to a single EC2 instance. Option C is wrong because EFS is a file system, not as cost-effective for large-scale data. Option D is wrong because Amazon FSx for HDFS is designed for HDFS compatibility but is more expensive than S3.
What should I do if I get this DEA-C01 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related DEA-C01 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 company is migrating an on-premises Hadoop cluster to AWS. The cluster processes large files in CSV format using Apache Spark. Which data store should be used as the primary storage for the data lake to optimize cost and performance?
medium
A.Amazon EMR File System (EMRFS) backed by HDFS
B.Amazon RDS for MySQL
C.Amazon EBS volumes attached to the EMR cluster
✓ D.Amazon S3
Why D: Option C is correct because Amazon S3 is the best choice for data lake storage due to its durability, scalability, and cost-effectiveness. Option A is wrong because EBS is block storage for EC2 instances, not suitable for large-scale data lakes. Option B is wrong because EMRFS is a connector for S3, not a separate storage. Option D is wrong because RDS is relational and not designed for large file storage.
Last reviewed: Jun 20, 2026
Question Discussion
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This DEA-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 DEA-C01 exam.
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