BTW, if you need a pure Go client for NFSv4 (including AWS EFS), feel free to check my: https://github.com/Cyberax/go-nfs-client
I’m not saying that S3 is perfect or even good for most workloads. However, it is most excellent when the workload fits.
In order to migrate off it and onto s3 I had to build a custom tool in rust that used libnfs directly to list the contents of the disk. We then launched a large number of lambdas to copy individual files to s3.
It was fun, but in my experience EFS is only good if you have a very homogenous workload and are able to carefully optimise metadata IO. I wouldn’t recommend it - s3 is just cheaper, faster and better.
I wouldn't use EFS to store petabytes of data, but if you need a resilient and scalable storage that you can easily integrate into your application, then EFS is great.
One thing that I loved, is the ease of use in local development. With EFS you can simply mount the shared volume into your Docker/K8s container in production, and a local directory when you're developing tasks locally on your laptop. You can even run tasks without a container and monitor their output by looking at the exchange directory. There are AWS API emulators (e.g. Localstack) but they are not as convenient.
note, I worked on Amazon at S3 2015-2017.
