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Storage & Data

GPU workloads are data-heavy. This page explains where data lives on a DC Suite cluster, how long it survives, and how to get results out before you tear a cluster down.

Storage tiers

A cluster typically presents three tiers, each with different speed and durability characteristics:

Tier Backed by Scope Survives cluster delete? Use for
Node-local scratch The node's own NVMe/SSD One node ❌ No Hot working set for a single node, checkpoints in flight
Shared cluster storage A cluster-wide shared filesystem All nodes in the cluster ❌ No Datasets and outputs shared across nodes/jobs
External / durable storage Object store or NFS you mount Outside the cluster ✅ Yes Source datasets, final artifacts, anything you must keep

Cluster-scoped storage is ephemeral

Both node-local scratch and shared cluster storage are destroyed when the cluster is deleted. Treat them as scratch. Anything you need to keep must land in external/durable storage before delete.

Shared cluster storage

When you create a cluster you set a shared storage quota (GiB). That capacity is presented as a shared filesystem mounted on every node, so a multi-node job can read inputs and write outputs to one place.

  • Sizing: set it to your dataset size plus headroom for outputs and checkpoints.
  • Path: the mount point is shown on the cluster's detail page.
  • Performance: shared storage is convenient but slower than node-local NVMe; for the hottest data, stage onto node-local scratch at job start.

A durable-data workflow

flowchart LR
    EXT[(External durable store)] -->|stage in| SH[Shared cluster storage]
    SH -->|per-job hot copy| LOC[Node-local scratch]
    LOC -->|checkpoints| SH
    SH -->|results out| EXT
  1. Stage in your dataset from durable storage to shared cluster storage once, at the start.
  2. For throughput-bound jobs, copy the hot subset to node-local NVMe.
  3. Write checkpoints to shared storage so a single node failure doesn't lose progress.
  4. Copy results out to durable storage before deleting the cluster.

Getting data in and out

  • Small files: scp/rsync over SSH to the login node.
  • Large datasets: pull directly from your object store on the cluster (e.g. with the provider's CLI) into shared storage — much faster than pushing from a laptop.
  • Results: push finished artifacts back to durable storage from a job's final step, so nothing depends on you remembering to copy before delete.

Checklist before deleting a cluster

  • [ ] Final artifacts copied to durable storage
  • [ ] Latest checkpoint safe outside the cluster
  • [ ] Nothing important left only on node-local scratch

Next: Security & Isolation.