Linux ECS Fargate tasks run in two AZs of the same VPC and need to read and write the same shared files. Each AZ has running application tasks; surviving tasks must use the same files after loss of one AZ.
EFS Regional is selected. Prepare an NFS-aware application, VPC routing, TCP 2049 permissions, file permissions, and retries. Choose the access configuration including the Fargate environment and task definition.
Which configuration is most appropriate?
Combine supported Linux Fargate, Regional access paths in the consuming AZs, and a task definition referencing the same EFS.
Detailed explanation
Fargate EFS support requires Linux platform 1.4.0 or later. A matching task definition cannot make an unsupported runtime support it.
Fargate EFS support requires Linux platform 1.4.0 or later. A matching task definition cannot make an unsupported runtime support it.
An environment variable alone does not mount an ECS EFS volume. The task volume and container mount configuration are required.
An environment variable alone does not mount an ECS EFS volume. The task volume and container mount configuration are required.
This combines supported execution, AZ access paths, and the task-to-container mount using the same Regional file system.
This combines supported execution, AZ access paths, and the task-to-container mount using the same Regional file system.
Matching paths do not share data between separate file systems. Separate One Zone systems do not replace storage of the same files in Regional EFS.
Matching paths do not share data between separate file systems. Separate One Zone systems do not replace storage of the same files in Regional EFS.
Check official documentation
Compare the following points with the official documentation.
Review ECS EFS platform support and the documented volumes, efsVolumeConfiguration, and mountPoints configuration.
Official references
- Official documentation 1
- Official documentation 2
- Official documentation 3
- Official documentation 4
- Official documentation 5
- Official documentation 6
What to confirm
Explain how to check the EFS ID, sourceVolume mapping, NFS path, permissions, and surviving AZ tasks.
Key points
- EFS Regional
- EFS mount target
- efsVolumeConfiguration
- mountPoints
- Fargate platform version
- TCP 2049
Notes
- Environment: AWS SOA-C03 exam guide and the linked AWS documentation
- Reviewed against the linked AWS documentation on 2026-10-07.
Foundation review
Connect supported Fargate to the task volume
Fargate EFS support requires Linux platform 1.4.0 or later. Use the same fileSystemId in volumes.efsVolumeConfiguration, and reference that volume name through container mountPoints.sourceVolume. An EFS ID environment variable alone does not mount it; separate file systems at matching paths do not share contents.
Prepare surviving AZ access as well as Regional storage
Regional stores data redundantly across AZs, but prepare mount targets and NFS paths in the consuming AZs too. Allow client outbound and target inbound TCP 2049, check file permissions, and configure application retries. Surviving AZ tasks must be running; a file system alone does not guarantee service placement or uninterrupted existing connections.
Additional access controls have prerequisites
EFS IAM authorization uses the task IAM role and requires transitEncryption enabled. Access points also require transit encryption; omit rootDirectory or set it to / so the access-point root applies. Do not assume the execution role alone supplies task file-access permissions. Check the controls actually enabled.