Skip to main content

Snapshots

Snapshots provide a point-in-time view of a database's store. In IOTA, the database snapshot captures a running database's view of the IOTA network from a particular node at the end of an epoch.

info

While validators can enable snapshots, they are typically most valuable for full node operators. Therefore, in the following sections, we'll focus on snapshots from the perspective of full node operators.

Snapshots of the IOTA network enable full node operators a way to bootstrap a full node without having to execute all the transactions that occurred after genesis. You can upload snapshots to remote object stores like S3, Google Cloud Storage, Azure Blob Storage, and similar services. These services typically run the export process in the background so there is no degradation in performance for your full node. With snapshots stored in the cloud, you're more easily able to recover quickly from catastrophic failures in your system or hardware.

To maintain a healthy IOTA network, IOTA encourages the IOTA community to bring up additional snapshots to ensure stronger data availability across the network.

Supported snapshot types​

IOTA supports two types of snapshots:

  • RocksDB snapshots
  • Formal snapshots
info

Formal snapshots are not suitable for use if you are running an RPC node that does any historical data lookups. For more information on node data management, see Data Management.

You can configure a full node snapshot to generate a state snapshot at the end of each epoch. A single full node can generate RocksDB snapshots, Formal snapshots, or both.

RocksDB snapshots​

RocksDB snapshots are a point-in-time view of a database store. This means that the snapshot keeps the state of the system at the moment it generates the snapshot, including non-pruned data, additional indices, and other data.

Formal snapshots​

Formal snapshots are database-agnostic, minimalistic snapshots containing only essential data for node restoration at a specific epoch. They offer smaller storage footprint and faster restoration compared to database snapshots. Natively supported by IOTA protocol, this means the snapshot contents can be cryptographically verified against the committee's epoch-end commitment, a process that occurs automatically during restoration (unless explicitly bypassed).

The formal snapshots have the following properties:

  1. Minimalism: Formal snapshots contain the end of epoch live object set (the set of all object versions eligible for use as input objects for future transactions) plus a small per-epoch metadata file covering every epoch since genesis. IOTA syncs all other critical chain information from the chain or derives it. Thus, formal snapshots contain only the necessary data required for a node to startup at epoch boundary and participate in the network.
  2. Agnosticism: Formal snapshots are by nature agnostic to the underlying database choice or implementation of the protocol. As the live object set is protocol defined, so is the formal snapshot.
  3. Verifiability: Formal snapshots have first-class support in the core IOTA protocol. As such, they must be trustless/verifiable by the node operator upon download. To support this, the protocol signs a commitment to the live object state at end of epoch, which formal snapshots are checked against at restore time. If this verification fails, the node state is moved back to the state before the snapshot restore attempt.

Because these snapshots do not contain transaction history, they are most immediately useful for validators and state sync full nodes (SSFNs). Restoring from a formal snapshot also builds the gRPC index store by default (pass --skip-grpc-indexes to opt out), so a full node started with the gRPC API enabled serves it right away without re-indexing the restored state. You can upload snapshots to remote object stores like S3, Google Cloud Storage, Azure Blob Storage, and similar services. These services typically run the export process in the background so there is no degradation in performance for your full node. With snapshots stored in the cloud, you can recover from catastrophic failures in your system or hardware more efficiently.

Enabling snapshots​

A nodes does not take snapshots by default. To enable this feature you must apply specific configs to your node.

Follow these steps to change the configs for the node:

  1. Stop your node, if it's running.

  2. Open your fullnode.yaml file and apply config updates as the following. Using Amazon's S3 service as an example:

    db-checkpoint-config:
       perform-db-checkpoints-at-epoch-end: true
       perform-index-db-checkpoints-at-epoch-end: true
       object-store-config:
          object-store: "S3"
          bucket: "`<BUCKET-NAME>`"
          aws-access-key-id: "`<ACCESS-KEY>`"
          aws-secret-access-key: "`<SHARED-KEY>`"
          aws-region: "`<BUCKET-REGION>`"
          object-store-connection-limit: 20
    • object-store: The remote object store to upload snapshots. Set as Amazon's S3 service in the example.
    • bucket: The S3 bucket name to store the snapshots.
    • aws-access-key-id and aws-secret-access-key: AWS authentication information with write access to the bucket.
    • aws-region: Region where bucket exists.
    • object-store-connection-limit: Number of simultaneous connections to the object store.
    • concurrency: Number of concurrent uploads of snapshots to the object store.

  3. Save the fullnode.yaml file and restart the node.

Restoring a full node from snapshots​

Restoring from RocksDB snapshots​

To restore from a RocksDB snapshot, follow these steps:

  1. Empty the snapshot directory specified by the db-path in your fullnode.yaml.

  2. Set the AWS_SNAPSHOT_ENDPOINT environment variable to the target snapshot URL. If not set, the default values are endpoints provided by the IOTA Foundation with public access:

  3. Download the snapshot for your target epoch to your local disk. Snapshots are stored per epoch in S3 buckets. For example, if you're restoring the latest epoch:

    iota-tool download-db-snapshot \
       --latest \
       --network mainnet \
       --path "<PATH-TO-NODE-DB>" \
       --num-parallel-downloads 25 \
       --skip-indexes \
       --no-sign-request \
       --verbose

    iota-tool options:

    • --epoch: The epoch that you want to download, for example 200. The buckets hosted by the IOTA Foundation will only keep the last 90 epochs, you can check the most recent epoch on the IOTA Explorer.
    • --latest: Rather than explicitly passing a epoch via --epoch, you can pass the --latest flag, which will automatically select the latest snapshot`
    • --network: Network to download snapshot for. Defaults to "mainnet".
    • --path: Path to snapshot directory on local filesystem.
    • --skip-indexes: Skips downloading the very large indexes/ dir, used by jsonrpc on the fullnode.

  4. Move the snapshot: The snapshot will be located in the epoch_[NUM] directory at your specified path. Move it to the snapshot directory specified by the db-path in your fullnode.yaml and mark the snapshot as live. For example, if db-path is /opt/iota/db and epoch_10 directory locates in /opt/iota/db, move the snapshot:

    mv /opt/iota/db/epoch_10 /opt/iota/db/live

  5. Update ownership: Make sure you update the ownership of the downloaded directory to the iota user (or whichever linux user you run iota-node as):

    sudo chown -R iota:iota /opt/iota/db/live

  6. Start your IOTA node.

Restoring from Formal snapshots​

To restore from a Formal snapshot, use the iota-tool binary. iota-tool can be downloaded along with other iota binaries. See Install IOTA for more details.

The following steps can be used to restore a node from a Formal snapshot:

  1. If it's running, stop the node.

  2. Pick your setup, network, and a snapshot epoch. Copy the resulting command and run it:

    Loading snapshot picker…
    • --epoch / --latest: Pin a specific snapshot epoch, or always grab the most recent one.
    • --genesis: The path to the location of the network's genesis.blob.
    • --network: Network to download snapshot for. Defaults to "mainnet".
    • --path: Path to snapshot directory on local filesystem.
    • --skip-grpc-indexes: Skips building the gRPC index store during the restore. By default it is built from the same object stream that restores the state, so a full node started with the gRPC API enabled opens it in place instead of re-indexing the whole restored state on first start. Skip it only if the node will never serve the gRPC API.

Backfilling the full checkpoint summary history​

A node restored from a formal snapshot holds only the end-of-epoch checkpoint summaries (one per epoch). That is enough to run, but the node cannot serve historical checkpoint queries below its restore point, nor act as a complete summary source for peers syncing the header chain. To fill in every intermediate summary from the checkpoint archive, stop the node and run:

iota-tool backfill-checkpoint-summaries \
   --path "<PATH-TO-NODE-DB>/live" \
   --num-parallel-downloads 50 \
   --verbose
  • --path: The node's live database directory (the one containing checkpoints/, store/, and epochs/). The network — and thus the archive bucket — is derived from the node's own genesis checkpoint, so no genesis file or network flag is needed. Override the bucket with the CUSTOM_ARCHIVE_BUCKET environment variables for a custom network.

Each downloaded summary is verified against the committee chain before it is stored. This only adds historical summaries below the node's existing watermarks — it never changes how far the node has synced or executed, and it never overwrites the summaries the node already has. It is safe to re-run.

IOTA Foundation managed snapshots​

The IOTA Foundation provides the public snapshot access: