EFS throughput mounted on many instances

Question

Hello,

i'm evaluating to use EFS as shared storage for 10 EC2 instances with a provisioned throughput of 120 MB/s but i don't clearly understand how this throughput is splitted between instances.

My questions is:

If i mount EFS to **1 instance**, **all 120 MB/s** **will be dedicated** to it...if mount EFS to **10 instances** and all instances are writing simultaneously on EFS, throughput will be **12 MB/s per instance**....but what about if only **1 of 10 instances** is writing on EFS, the EFS throughput will be **120 MB/s** or **12 MB/s**?

Thanks in advanced!

Accepted Answer

Hello

EFS throughput works at the file system level. You can read more about throughput at following link. It talks about various modes (bursting vs provisioned) for performance as well as how throughput is calculated. 
https://docs.aws.amazon.com/efs/latest/ug/performance.html

In the example provided, if you configure a file system with 120MB/sec and only 1 client is accessing it, then it will have 120MB/sec throughput available. If there are 10 clients, then at given time, the combined throughput can be 120MB/sec [if you are generating equal load from all 10 clients, then in theory, each client will peak at 10 MB/sec].

The maximum throughput you can drive for each NFS client is 500 MB/sec You can read more about it at following link:
https://docs.aws.amazon.com/efs/latest/ug/limits.html

How to manage throughput?
https://docs.aws.amazon.com/efs/latest/ug/managing-throughput.html

EFS throughput mounted on many instances

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