The section Environment requirements mentions that it is required:

Persistent volumes

• 4 RWO (ReadWriteOnce) persistent volumes for Redis, MySQL, and System-searchd persistence.
• 1 RWX (ReadWriteMany) persistent volume for Developer Portal content and System-app Assets.

However when using Amazon Simple Storage:

Persistent volumes

• 3 RWO (ReadWriteOnce) persistent volumes for Redis and MySQL persistence.

Storage
1 Amazon S3 bucket
NFS

Expected
When using Amazon Simple Storage NFS storage is not needed, and system-searcd PV should be added as per the previous description.  Amazon S3 is only used for system-storage.