MLS-C01 Data Engineering Practice Question
A data engineer needs to transfer 50 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The on-premises network has a 100 Mbps connection to AWS. The transfer must be completed within one week. Which approach should the engineer use?
⚠ Common exam trap
The trap here is that candidates may overestimate the effectiveness of acceleration or parallelization techniques, failing to calculate that a 100 Mbps link can only transfer approximately 1.08 TB per day, making any network-based option mathematically impossible for 50 TB in one week.
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
✓
Use AWS Snowball Edge device to physically transfer the data.
The on-premises network has a 100 Mbps connection, which yields a theoretical maximum transfer of about 1.08 TB per day (100 Mbps * 86400 seconds / 8 bits per byte / 1024^4 bytes per TB). To transfer 50 TB within 7 days, the required throughput is approximately 7.14 TB per day, far exceeding the available bandwidth. AWS Snowball Edge provides a physical shipping method that bypasses network constraints entirely, making it the only viable option for this volume and timeline.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Use AWS Snowball Edge device to physically transfer the data.
Why this is correct
Snowball Edge can handle large data volumes without network limitations.
- ✗
Use Amazon S3 Transfer Acceleration.
Why it's wrong here
Acceleration improves speed but not enough for 50 TB in a week.
- ✗
Use AWS DataSync to transfer the data over the network.
Why it's wrong here
DataSync uses network; 50 TB over 100 Mbps would take ~50 days.
- ✗
Use multiple concurrent AWS CLI copy commands over VPN.
Why it's wrong here
Still limited by network bandwidth; not sufficient.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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5 more ways this is tested on MLS-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 data engineer needs to transfer 50 TB of historical data from an on-premises HDFS cluster to Amazon S3. The company has a 1 Gbps internet connection. Which service would complete the transfer in the shortest time?
easy- ✓ A.AWS Snowball
- B.Amazon S3 Transfer Acceleration
- C.AWS Direct Connect
- D.AWS DataSync
Why A: AWS Snowball is the correct choice because transferring 50 TB over a 1 Gbps internet connection would take approximately 5.5 days (50 TB × 1024 GB/TB × 8 bits/byte ÷ 1 Gbps ÷ 86400 seconds/day), assuming full utilization, which is unrealistic due to overhead and contention. Snowball provides a physical appliance that can be loaded with data locally and shipped to AWS, completing the transfer in a few days including shipping time, making it faster than any network-based method for this volume.
Variation 2. A data engineer needs to transfer 50 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The on-premises network has a 1 Gbps connection to AWS. The transfer must be completed within 10 days. What is the MOST efficient approach?
easy- ✓ A.Use AWS Snowball Edge to physically ship the data.
- B.Use Amazon S3 Transfer Acceleration to speed up the upload.
- C.Use AWS DataSync over the existing network connection.
- D.Set up a VPN connection and use multi-part upload directly to S3.
Why A: Transferring 50 TB over a 1 Gbps connection would take approximately 5.6 days under ideal conditions (50 TB × 8 bits/byte / 1 Gbps / 86400 seconds/day ≈ 4.63 days), but real-world factors like network congestion, TCP overhead, and protocol inefficiencies typically reduce throughput to 50-70% of line rate, pushing the transfer beyond the 10-day window. AWS Snowball Edge provides a physical shipping alternative that bypasses network limitations entirely, making it the most efficient and reliable method for this volume and deadline.
Variation 3. A data engineer needs to transfer 50 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The company has a 1 Gbps internet connection and wants to complete the transfer within 5 days. What is the MOST cost-effective and reliable solution?
medium- ✓ A.Use AWS Snowball Edge device to physically ship the data
- B.Use S3 multipart upload over the internet
- C.Set up AWS Direct Connect and transfer over the dedicated line
- D.Use S3 Transfer Acceleration to speed up the transfer
Why A: AWS Snowball Edge is the most cost-effective and reliable solution because transferring 50 TB over a 1 Gbps internet connection would take approximately 5.5 days under ideal conditions (50 TB * 1024 GB/TB * 8 bits/byte / (1 Gbps * 86400 seconds/day) ≈ 4.74 days, but real-world overhead, congestion, and retransmissions push it beyond 5 days). Snowball Edge provides a physical appliance that can be shipped, avoiding network bandwidth limitations entirely, and is designed for large-scale data transfers where internet speeds are insufficient.
Variation 4. A data engineer needs to transfer 50 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The company has a 100 Mbps internet connection and a tight deadline of two weeks. Which AWS service should the engineer use to transfer the data most efficiently?
easy- A.AWS Storage Gateway (Volume Gateway)
- ✓ B.AWS Snowball Edge
- C.Amazon S3 Transfer Acceleration
- D.AWS DataSync over the internet
Why B: B is correct because transferring 50 TB over a 100 Mbps connection would take approximately 48 days (50 TB * 8 / 100 Mbps / 86400 seconds/day), far exceeding the two-week deadline. AWS Snowball Edge is a physical data transport device that can securely transfer petabytes of data offline, bypassing network bandwidth constraints entirely. For large datasets and tight deadlines, Snowball Edge is the most efficient AWS service.
Variation 5. A data engineer needs to transfer 50 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The company has a 100 Mbps internet connection and the data must be transferred within 5 days. Which AWS service is best suited for this task?
easy- A.AWS DataSync
- ✓ B.AWS Snowball Edge
- C.Amazon S3 Transfer Acceleration
- D.AWS Storage Gateway
Why B: AWS Snowball Edge is a physical device designed for large-scale data transfer, ideal for moving 50 TB of data when network bandwidth (100 Mbps) is insufficient to meet the 5-day deadline. Option A is wrong because AWS DataSync is a network-based service; transferring 50 TB over 100 Mbps would take approximately 50 days, far exceeding 5 days. Option C is wrong because Amazon S3 Transfer Acceleration improves transfer speeds over the internet but cannot overcome the 100 Mbps bandwidth limitation; it would still take too long. Option D is wrong because AWS Storage Gateway is for hybrid cloud storage with a local cache, not for one-time bulk data migration.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This MLS-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 MLS-C01 exam.