What is the total number of EFS volumes that can be created in a VPC?

Yes, you're correct. My plan is to isolate compute and storage for each customer via Lambda and EFS.

Using Access Points does seem like a possible solution. I was using an IAM policy to restrict the access to the filesystem, and it looks like I can do something similar with access points. This does have a few drawbacks though:

• Data isn't truly isolated, is enforcing a root directory enough?
• Would lose the ability to encrypt the data with distinct keys per customer
• Customers would share IOPS which would force me to use Max/IO instead of General Purpose performance which is slower

Access points are limited to 120 per file system. So this would only help if you add complex logic to organize which access point of which EFS volume should be used for each case.

The alternative way to scale would be to create more VPCs so that you can have more EFS volumes with mount points, but then to connect them you'd need some complex VPC peering set up.

Thanks for the suggestion but Amazon FSx for Ontap doesn't seem to fit the use case based on price.

Noting: FSx seems to have a default quota of 100 Filesystems per AWS account. You can request quota increases, though it is not clear to what limit. So this may be more restrictive than the 133 EFS volumes per VPC.