> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fireworks.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Advanced: Incremental Snapshots

> Reference notes for ARC2 incremental snapshots in BYOT RL rollout integrations.

<Warning>
  **Early Access Feature.** This page is part of the same private-preview
  external-bucket hot-load workflow for RL rollouts. Contact Fireworks to enable
  this path on your account before using non-`FW_HOSTED` storage.
</Warning>

<Note>
  Most readers should follow the linear workflow in [RL Rollouts with Your Own
  Trainer](/fine-tuning/rl-rollout-integration). This page is only for advanced
  BYOT integrations or lower-level troubleshooting.
</Note>

Use incremental snapshots between full snapshots to reduce upload and load time during RL training.

Recommended cadence:

* **First snapshot:** full.
* **Every 20th or 30th snapshot:** full.
* **All other snapshots:** incremental against the currently loaded snapshot.

## Reference

* Give every snapshot a new `identity`.
* Point `incremental_snapshot_metadata.previous_snapshot_identity` at the previous snapshot in the chain.
* Use ARC2 (`arc_v2`) for `incremental_snapshot_metadata.compression_format`.
* Upload the incremental snapshot under the normal snapshot directory for the new `identity`.
* If an incremental hot-load fails, fall back to a new full snapshot.

## Related pages

<CardGroup cols={2}>
  <Card title="Full integration guide" icon="rotate" href="/fine-tuning/rl-rollout-integration">
    The end-to-end BYOT flow.
  </Card>

  <Card title="Ledger & debugging" icon="bug" href="/fine-tuning/rl-rollout-debugging">
    Inspect snapshot history and recover from a broken chain.
  </Card>
</CardGroup>