MySQL Migration with Minimal Downtime using AWS DMS
A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database is 500 GB in size and has a 24-hour maintenance window. Which AWS service or tool should be used for the initial data transfer with minimal downtime?
Quick Answer
The answer is AWS Database Migration Service (DMS). AWS DMS is the correct choice for a MySQL migration with minimal downtime because it supports ongoing replication from the source on-premises database to the target Amazon RDS for MySQL, allowing you to keep both databases in sync during the transition. This means you can cut over to the new RDS instance in seconds, rather than taking the database offline for the full 500 GB transfer. On the AWS Certified Database Specialty DBS-C01 exam, this question tests your understanding of migration strategies that balance data volume with availability requirements—specifically, that DMS’s change data capture (CDC) feature enables near-zero downtime even for large databases. A common trap is choosing AWS Snowball for the initial load, but Snowball lacks continuous replication, so it cannot minimize downtime during a live migration. Remember the memory tip: “DMS syncs, Snowball ships”—if you need ongoing replication to avoid downtime, DMS is the only service that keeps your data flowing without interruption.
⚠ Common exam trap
A common mix-up: candidates choose mysqldump (Option D) because it is familiar and free, but they overlook that it requires locking tables or stopping writes, which violates the 'minimal downtime' requirement for a 24-hour maintenance window.
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
✓
AWS Database Migration Service (DMS)
AWS Database Migration Service (DMS) is the correct choice because it supports ongoing replication from a source MySQL database to Amazon RDS for MySQL, allowing you to perform a full load followed by continuous change data capture (CDC) to minimize downtime. With a 500 GB database and a 24-hour maintenance window, DMS can complete the initial load and then keep the target in sync until you cut over, achieving near-zero downtime.
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 S3 with AWS Glue
Why it's wrong here
Glue is for ETL, not for live database migration.
- ✗
AWS Snowball Edge
Why it's wrong here
Snowball is for offline data transfer and does not support continuous replication.
- ✓
AWS Database Migration Service (DMS)
Why this is correct
DMS supports ongoing replication from on-premises to RDS, minimizing downtime.
- ✗
mysqldump and restore to RDS
Why it's wrong here
mysqldump requires downtime and does not support ongoing replication.
Go deeper
Related to this question
About these practice questions
One of 1,663 original DBS-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on DBS-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 is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database is 2 TB in size and the network bandwidth is 100 Mbps. The company needs to minimize downtime. Which migration strategy should be used?
easy- ✓ A.Use AWS Database Migration Service (DMS) with ongoing replication.
- B.Copy database files to Amazon S3, then restore to RDS using native restore.
- C.Use mysqldump to export the database and import it into RDS.
- D.Use AWS Server Migration Service to migrate the database server.
Why A: AWS DMS with ongoing replication is the correct strategy because it allows you to perform a full load of the 2 TB database while simultaneously capturing ongoing changes from the source MySQL binlog. This minimizes downtime by enabling a cutover with only a brief pause to ensure replication lag is zero, rather than requiring a long period of application downtime for a full export and import.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.