Cost-Effective EFS Cross-Region Replication Solution

SAA-C03 By islever Editorial Last updated

Determine appropriate data security controls.

Short answer

A Use the EFS-to-EFS backup solution to replicate the data to an EFS file system in another Region.

Question

A company runs an application on several Amazon EC2 instances that store persistent data on an Amazon Elastic File System (Amazon EFS) file system. The company needs to replicate the data to another AWS Region by using an AWS managed service solution. Which solution will meet these requirements MOST cost-effectively?
  1. Use the EFS-to-EFS backup solution to replicate the data to an EFS file system in another Region. Correct Answer
  2. Run a nightly script to copy data from the EFS file system to an Amazon S3 bucket. Enable S3 Cross-Region Replication on the S3 bucket.
  3. Create a VPC in another Region. Establish a cross-Region VPC peer. Run a nightly rsync to copy data from the original Region to the new Region.
  4. Use AWS Backup to create a backup plan with a rule that takes a daily backup and replicates it to another Region. Assign the EFS file system resource to the backup plan.

Key Takeaways

Tests the distinction between 'backup' and 'replication' capabilities of AWS Backup versus native EFS features, highlighting that native replication is often free while backups incur storage costs.

Determines the most cost-effective AWS managed service for replicating Amazon EFS data across regions by evaluating native replication versus backup services.

Common mistake: Selecting AWS Backup (D) because it is a fully managed service, ignoring that EFS-to-EFS replication is also managed, more direct, and typically cheaper as it avoids redundant storage fees.

Expert Analysis

Why the Answer Is Correct

Option A is correct because Amazon EFS offers a native EFS-to-EFS backup/replication feature that allows you to replicate file systems to another region. This solution is considered 'AWS managed' as it is built into the EFS service without requiring third-party scripts or complex infrastructure setup like VPC peering and rsync. It is the most cost-effective because it does not require maintaining a separate copy in a different storage class (like S3) or paying for daily incremental backups if only a single replicated instance is needed; it simply maintains a live mirror. Note: While the option text says 'EFS-to-EFS backup', this refers to the native replication capability introduced by AWS.

Why the Other Options Are Wrong

Option D (AWS Backup) is a strong distractor because it is a fully managed service. However, AWS Backup creates point-in-time snapshots. To have active data in another region via AWS Backup, you would need to restore from these snapshots, which incurs storage costs for the backups and potentially restoration time/costs. Native replication (A) keeps a continuous copy, which is generally more efficient for 'replication' use cases than periodic backups. Options B and C involve custom scripting (rsync, nightly scripts) and infrastructure management (VPC, cross-region links), which violate the 'AWS managed service solution' requirement.

Community Comment Notes

Many users selected D arguing that AWS Backup is the only 'fully managed' service, overlooking that EFS replication is also managed. User sandordini noted that EFS-to-EFS backup must be in the same region, which is incorrect for the replication feature but highlights confusion. User Nm55569 correctly pointed out that EFS replication is managed, cheapest (only paying for transfer/storage of the replica, not extra backup tiers), and linked to official docs. The consensus on the page leans towards D due to the word 'managed', but A is technically superior for cost and direct replication requirements.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When a question asks for a 'managed service' for replication, look for native service features first (like EFS Replication, RDS Multi-AZ/Read Replicas) before jumping to generic services like AWS Backup or Storage Gateway. Native features are often more cost-effective for simple replication tasks.

Frequently Asked Questions

Is EFS-to-EFS replication considered an AWS managed service?

Yes, it is a native feature of Amazon EFS that requires no infrastructure management, fitting the definition of an AWS managed service.

Why is AWS Backup not the most cost-effective choice here?

AWS Backup stores snapshots, incurring ongoing storage costs. Native replication maintains a live copy which can be more efficient for continuous availability needs without extra backup tier fees.

More SAA-C03 FAQ →

Community Votes

D
69%
A
31%

69% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 14 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 14

  1. sandordini 👍 7 Answered D
    NOTA: EFS-to-EFS backup: You must deploy this solution in the same AWS Region as your source Amazon EFS Folesystem Not B, C: Not a managed AWS Solution D: AWS backup will do the job, and is managed service.
  2. EdricHoang 👍 5 Answered D
    A is oke but it says "'AWS managed service solution" So I go for D
  3. Nm55569 👍 4 Answered A
    Aws backup is not replicating. Efs replication is and it's managed in that you configure it and then it does the replication - no further actions required. It's also cheapest since it's free, you just pay for data transfer and storage https://docs.aws.amazon.com/efs/latest/ug/efs-replication.html https://aws.amazon.com/blogs/aws/new-replication-for-amazon-elastic-file-system-efs/
  4. xBUGx 👍 3 Answered A
    To replicate data from an Amazon Elastic File System (EFS) file system to another AWS Region, the MOST cost-effective solution would be to use EFS Replication. Here’s why: EFS Replication: EFS Replication allows you to natively create a copy of your file system in an AWS Region or Availability Zone (AZ) of your choice. It automatically and transparently copies your data from the source file system to the destination, maintaining an RPO (Recovery Point Objective) of 15 minutes for most file systems. This solution is specifically designed for replicating EFS data across Regions, ensuring data resilience and protection. There are no additional costs for using replication failback, and you pay for the usual replication and file system changes as described in Amazon EFS pricing12. EFS Replication is available in all AWS Regions where EFS is available1.
  5. NSA_Poker 👍 3 Answered D
    (A,B,C) are eliminated. They are NOT managed service solutions. (D) is correct. 'AWS Backup offers a cost-effective, FULLY MANAGED, policy-based service that simplifies data protection at scale.' https://aws.amazon.com/getting-started/hands-on/amazon-efs-backup-and-restore-using-aws-backup/
Show 9 more comments
  1. BatVanyo 👍 3 Answered D
    To me "an AWS managed service solution" automatically translates to AWS Backup. ...Can't say if this is cheaper than EFS replication tho.
  2. Rahulmaddy 👍 3 Answered A
    A is cheaper and less complicated to impliment compared to D
  3. Scheldon 👍 2 Answered D
    AnswerD I think the most cost effective would solution presented in C, but hence in question it's clearly wrote that we should use AWS Managed Services Solution, hence I think we have no other choice then to choose AWS backup (Option D)
  4. Madushanka 👍 2
    Answer D: AWS Backup is a managed service that handles backup operations. If AWS Backup is not available in your region, you can consider using EFS-to-EFS backup
  5. mk168898 👍 2
    AWS backup is the only managed service so D
  6. LeonSauveterre 👍 1 Answered D
    While EFS-to-EFS replication (Option A) is great for real-time replication, Option D (AWS Backup) is the more cost-effective choice for long-term retention and administrative simplicity. Also, I copied this from somewhere: EFS-to-EFS Replication might not technically be an "AWS Managed Service" in the same sense as services like AWS Backup or Amazon RDS, but it is a solution supported by AWS. The process is automated in the sense that AWS handles the replication between EFS file systems, but it does not provide the same level of managed service (like backup solutions) that abstracts away storage, retention, and backup policy management. However, the EFS-to-EFS solution is often classified under the broader umbrella of AWS managed solutions, since it directly integrates with EFS, but AWS Backup may provide a more clear-cut "AWS managed" approach with better control over backup policies and retention.
  7. expouser 👍 1
    A: Replication is available in all AWS Regions in which EFS is available. To use replication in a Region that is disabled by default, you must first opt in to the Region. For more information, see Managing AWS Regions in the AWS General Reference Reference Guide. If you later opt out of a Region, Amazon EFS pauses all replication activities for the Region. To resume replication activities for the Region, you need to again opt in to the AWS Region. https://docs.aws.amazon.com/efs/latest/ug/efs-replication.html
  8. 0bdf3af 👍 1
    A. you can replicate to another Region
  9. Cpso 👍 1 Answered D
    A-D : managed solution Cost D<A

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