If you run it at a higher level of abstraction than linode volumes with parity and can tolerate up to 8 drives / 1 server going down at once (like this setup on

If you run it at a higher level of abstraction than linode volumes with parity and can tolerate up to 8 drives / 1 server going down at once (like this setup on minio should get you), that would take you a long ways towards adding one or two 9's. High availability is just one S3 feature though. Other important features are paying for what you use, and effectively unlimited storage growth (you will probably revisit this before you hit $32k/mo the 320TB would cost). Even if this didn't add reliability, those other features still have utility above the raw Block Storage Volumes provided by linode here.