Per-accelerator I/O guidance sets the floor. Multiply it by your fleet and the storage tier either meets that number or your accelerators wait. The arithmetic is boring, which is exactly why it gets skipped.
A 10,000-GPU cluster running at 98% storage availability loses roughly 1,752,000 GPU-hours a year. Not to a catastrophic outage, just to the 2%. On a training fleet, every hour the storage tier is degraded is an hour the whole job is degraded with it.
This is why the resiliency story belongs in the same conversation as throughput. Multi-level erasure coding scopes a failure to a single VPOD, self-healing rebuilds run in the background, and upgrades happen in place, so the fleet keeps training.
Whether you rent capacity out or run your own frontier training, the economics are the same: utilization is margin, power is the ceiling, and cost per token is the scoreboard.
Preprocessing, sharding, epoch reads, checkpoint bursts, and evaluation each hit storage differently. On VDURA they all live on the same platform, so nothing gets copied between stages and nothing waits on an external S3 pipe.
At thousands of accelerators, component failure is continuous, not exceptional. Every failure costs you the progress since your last checkpoint, plus the time to reload and resume. Stretch the interval and both losses grow.
VDURA lands checkpoint and optimizer state as parallel burst writes across flash nodes; V12 snapshots version every checkpoint instantly. Cheap checkpoints mean frequent checkpoints, and parallel reads reload state fast enough that a failed run resumes instead of restarting.
Run your checkpoint math with usEvery DirectFlow client stripes files wide across storage nodes simultaneously, over RDMA or TCP, with client-side erasure coding and full cache coherence. No NFS choke point, no controller pair, no scale-out NAS pretending to be parallel. Throughput scales with node count, linearly, all the way up.