EFS vs EBS mult-attach

I want to elaborate a bit on some of the differences between EBS multi-attach and EFS.

EFS is a fully-managed file system service. It's fully elastic, growing and shrinking as you add and remove files, so you don't need to worry about manually managing capacity, either to accommodate growth, or to optimize utilization - you pay only for the storage that you use. EBS multi-attach volume's don't support re-sizing capacity once they are created.

EFS is also designed for high availability and high durability. To achieve these levels of availability and durability, EFS automatically replicates data within and across 3 Availability Zones, with no single points of failure. EBS multi-attach volumes can be used for clients within a single Availability Zone. If there is a volume failure at the EBS infrastructure layer, all clients will be impacted.

EFS also has a number of 'bells and whistles' in terms of features and integrations with other services - things like automatic cost optimization with EFS Infrequent Access and Lifecycle Management, IAM authn/authz and Access Points, integration with AWS Backup, and integrations with services like ECS and SageMaker.

Overall, while it's natural to do a list price comparison between services, often times it won't be apples-to-apples. We recommend looking at the workload requirements, including price, but also multi-AZ availability/durability, ease of management/elasticity, performance and concurrent access, and integrations, among others.