Basic Information
| Field | Details |
|---|---|
| English name | Amazon EFS |
| Full name | Amazon Elastic File System |
| Chinese description | 弹性共享文件系统 |
| Japanese description | 共有ファイルストレージ |
| Exam frequency | ⭐⭐⭐⭐ |
| Often confused with | EBS / S3 / FSx |
In one sentence
EFS provides familiar directory and file semantics, allowing several EC2 instances or containers to share the same path.
Core purpose
- Standard file systems are regional and multi-AZ by design; One Zone is also available.
- Create mount targets in the AZs you use and allow NFS TCP 2049 in security groups.
- Capacity scales automatically, and lifecycle policies can move cold files to IA or Archive.
Exam focus
- Linux, NFS, and shared multi-instance directories point to EFS.
- Use EBS for blocks and database disks, S3 for object APIs, and FSx for specialized file systems.
- EFS is not a global file system; cross-VPC or cross-Region access still needs networking.
Common misconceptions
- Automatic capacity growth does not guarantee unlimited throughput.
- Multi-AZ design does not remove mount-target and security-group requirements.
Key takeaway
Choose EFS for a shared Linux directory and S3 for object APIs.
Related services
EC2, ECS, EKS, NFS, FSx, AWS Backup.