Anyone using EFS for 20+TB?

Hi, thanks for reaching out. I'm on the EFS service team, and can confirm that EFS file systems support PiB-scale, and many customers are using EFS and Backup successfully within and above the size range of 20TiB-100TiB that you mentioned.

Based on your current usage of both EBS GP2 and SC1 it sounds like your use case would be a great candidate for EFS Lifecycle Management, which moves less active data to our EFS Infrequent Access storage class at a 92% lower cost. On average, customers that use this capability achieve blended storage cost of $0.08/GiB-mo or less.

EFS supports both encryption at rest and encryption-in-motion. You can enable the former at file system creation time with a single click, and the latter is a per-connection option when using our EFS mount helper utility.

For backups, you can configure your AWS Backup policy to run as often as every hour by using a custom cron expression in your backup rule configuration. Your first backup will make a fully copy of your file system, and subsequent backups will be incremental-only. You can also configure your backup policy to store some or all backups in another AWS Region.

Last, it's unlikely that you need to create multiple file systems to store your data, since each EFS file system elastically scales to PB-scale, and supports up to 35K IOPS and several GB/s of aggregate throughput.