> You can't go with a single instance and a ton of EBS storage, because it caps out at 16TB of disk
I just used the calculator to price out a single instance without issue. Just type in nineteen 16TB EBS volumes (you’d create an LVM volume group for them if launched). I used to have EC2 instances (albeit not by choice, I inherited the bad architecture) with 42TB total of EBS volumes using LVM without issue.
I didn't realise they'd upped the maximum volume size from 1TB to 16TB, so thought the calculator was telling me it was capped at 16x EBS volumes per instance. The new calculator isn't helping things here[1] telling me that I can only assign 16TB to an instance.
So, given that - then the issue becomes is 25Gbit NIC / 19Gbit EBS bandwidth enough IO to at least equal the needs of the task.
On paper the total bandwidth of the author's disk controller was 24Gbit, but that will depend on how the output is spread and whether the EBS limit includes any overheads that aren't present in DAS.
Interestingly, if the requirements are mostly sequential, you can get better performance/$ going with throughput-optimised HDDs rather than gp2 SSD.
Applying striping in either case will ensure you saturate the per-instance EBS bandwidth limits.
I just used the calculator to price out a single instance without issue. Just type in nineteen 16TB EBS volumes (you’d create an LVM volume group for them if launched). I used to have EC2 instances (albeit not by choice, I inherited the bad architecture) with 42TB total of EBS volumes using LVM without issue.