> For the complete documentation index, see [llms.txt](https://whitepaper.litho.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://whitepaper.litho.ai/docs/validators/ledger-sync-service.md).

# Ledger Sync Service

> **Work in Progress** -- This page is under active development. Content will be expanded as implementation details are finalized.

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## Topics to Cover

The following topics will be documented in this guide:

### Sync Modes

* **Fast Sync** -- Rapidly catch up to the current chain height by downloading and verifying blocks in parallel without replaying all transactions.
* **Full Sync** -- Replay every block from genesis to reconstruct the complete chain state. Provides the highest level of verification but takes significantly longer.

### Genesis Sync Process

Step-by-step process for syncing a new node from the genesis block, including genesis file retrieval, peer configuration, and expected sync timelines.

### Snapshot-based Sync

Using state snapshots to bootstrap a node to a recent chain height without replaying historical blocks. Covers snapshot providers, verification of snapshot integrity, and restore procedures.

### State Pruning Strategies

Configuration options for managing on-disk state growth:

* **Default pruning** -- Retains recent state only.
* **Nothing** -- Retains all historical state (archive node).
* **Everything** -- Aggressive pruning for minimal disk usage.
* **Custom** -- Fine-grained control over pruning intervals and kept versions.

### Peer Discovery

How nodes discover and connect to peers on the Lithosphere network, including seed nodes, persistent peers, and the address book.

### Data Directory Management

Best practices for managing the `~/.lithod/data/` directory, including backup strategies, disk space monitoring, and safe data directory relocation.

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## Configuration Reference

Sync behavior is primarily controlled through `config.toml`. Key sections include:

* `[statesync]` -- State sync configuration (enable, RPC servers, trust height/hash)
* `[p2p]` -- Peer-to-peer networking (seeds, persistent peers, max connections)
* `[fastsync]` -- Fast sync version selection

Refer to the inline comments in `config.toml` for detailed parameter descriptions.

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## Related Pages

* [Node Deployment](/docs/validators/node-deployment.md) -- Initial node setup and installation