AWS EFS- Elastic File System

Amazon EFS Architecture

EFS is a file system based storage where files are stored as Chunks and they only those chunks gets modified when modification happens.

EFS can be attached to multiple EC2 instances, however those regions should belong to the same EC2 instance region

EFS is recommended in use cases where in multiple read/write happens.

It offers two Performance modes: You can choose the performance mode by running your web application in general mode and then Monitor the PercentIOLimit Amazon CloudWatch metric for Amazon EFS during the performance test.

1. General Purpose- This mode supports low latency and upto 7000 operating system IO operations/second. In case you have more than or equal to 7000 operating system IO operations/second then you can use 2nd mode i.e. MAX I/O. General Purpose is ideal for latency-sensitive use cases, like web serving environments, content management systems, home directories, and general file serving.
2. MAX I/O- This mode provides high latency and it is recommended only when Operating system IO operations is equal to or exceeds 7000. It is recommended for Meta-Data storage and similar use cases where in high latency is permissable

Throughput mode:

1. Bursting- Throughput scales with filesystem size
2. Provisioned- Throughput is fixed at a particular amount

Encyption:

1. Encryption at rest using KMS- This is completely managed within KMS. When you create a new file system using the Amazon EFS console, encryption at rest is enabled by default.
2. Encryption of data in transit- Enabling encryption of data in transit for your Amazon EFS file system is done by enabling Transport Layer Security (TLS) when you mount your file system using the Amazon EFS mount helper.