[sparrc]

In my experience the biggest drawback with EFS is startup time for systems that mount it in.

For example a container or EC2 instance might only need a tiny bit of your storage and with s3 can just download what it needs when it needs it.

As opposed to EFS where the container or instance needs to load in the entire datastore on startup which can add minutes to startup time if the EFS drive is large.

[dpedu]

My understanding is that EFS is exposed as an NFS share. I haven't used it personally, but NFS mounting is generally fast, nearly instant. What does "load in the entire datastore" mean?

[ericpauley]

EFS mounting is definitely nearly instant. I use it constantly.

[dekhn]

Many servers start up, load a ton of data from storage into RAM, and then happily serve that data for a long time. The latency of the server when starting up before it can service its first request is entirely based on the throughput of the data load.

Often these servers will load 128+GB of data into RAM (crazy, huh?) and even if you have 1GB/sec it's still two minutes for the server to start up.

[dpedu]

1GB/s is the same speed from EFS or S3.

[dekhn]

I didn't say otherwise.