[manacit]

Just to address the core of your comment, 20 magnetic disks would combine for about ~2,000 IOPS of capacity, provide for no redundancy, and allow only one machine to process the entirety of the queries coming in to power the application.

Even a full 60 disk server filled with magnetic disks would provide less I/O capacity for running a relational database than a single EBS volume.

It's might not look like a lot of data if you're talking about storing media files, but it's quite a bit of relational data to be queried in single-digit milliseconds at-scale.

[znpy]

I assumed people did not need to be explicitly reminded that you had to provision additional capacity for redundancy, and that you can use different layers of caching (ssd caches, ram caches etc).

And by the way, it was just posted today that you can get 60TB pci gen5 SSDs from Micron: https://news.ycombinator.com/item?id=42122434 : you can still fit all that dataset in a single machine and provide all the iops you need. You'd need just 7 of those.

So yeah, 400TB of data is not much data nowadays.