[Fargate] [request]: Increase maximum ephemeral storage for tasks beyond 200 GiB

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**Tell us about your request**

In 2021, the maximum ephemeral storage for tasks was increased to 200 GiB (ref: #384). I would like to further increase that limit. I don't currently have a concrete target in mind and would defer to the AWS team on what (if any) sort of increase is feasible.

**Which service(s) is this request for?**

Fargate

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**

I run a Fargate service where each task pulls data from S3 upon starting up. The data must live in the task's ephemeral storage for performance reasons — operating on it across a network boundary is not an option. I love being able to use Fargate instead of managing my own fleet of EC2 instances and would like to continue down this path for as long as possible. However, the amount of data that each task pulls down will continue to grow over time and at some point eclipse 200 GiB. There are some mitigations I can implement to forestall that inevitability, and, in fairness, I will likely have to migrate off of Fargate at some point no matter how high the ephemeral storage limit is raised. My immediate goal for this request is to get a sense of whether 200 GiB is a reasonably hard cap for the foreseeable future (so I should start on my migration away from Fargate sooner) or if there's some wiggle room, which would relieve some of the urgency to explore alternatives.

**Are you currently working around this issue?**

No.

**Additional context**

None.

**Attachments**

None.