EFS is service provided by AWS for corporate if they want to attach it to multiple ec2 instances. Also it is automatically scale down/up based on the storage. But how is EFS build ? Is it built on EBS? EFS is file level storage, but files also need to be stored on disk in block level(agree object store like S3 its stored differently). So I am not able to capture the difference very well. So EFS data behind the scenes is it stored on EBS?

CodePudding user response：

AWS does not disclose implementation details of their services.

However, if you wish to "capture the difference":

• Amazon EBS acts like a Network-attached disk (NAS). It appears as a traditional hard disk and the computer's Operating System is responsible for storing data on the disk, maintaining the directories, handling permissions, etc.
• Amazon EFS is a network filesystem (SAN) that is managed by a server. The computer uses a network protocol to send/receive files, but does the Operating System is not responsible for how the data is stored on the disk (that is managed by the server).

Things are getting a little more complicated now that Amazon EBS allows volumes to be mounted on multiple Amazon EC2 computers.

Also, Amazon EBS is stored in only one Availability Zone whereas Amazon EFS filesystems are replicated across Availability Zones.

Summary

• Computers (eg Amazon EC2 instances) expect to have a local disk with an operating system and applications. This is the job of Amazon EBS.
• Computers on a network that wish to share data want to use a network filesystem. This is the job of Amazon EFS.