How to re-sync using checkpoint sync

Common reasons for re-syncing include:

🦉 Missed upgrade: Hard fork occurred and I forgot to update my consensus client

💾 Low disk space: I'm running low on disk space and would like to recover space

Step 1: Stop consensus client

sudo systemctl stop beacon-chain

Step 2: Remove consensus client database directory

Prysm

sudo rm -r ~/.eth2/beaconchaindata

Lodestar

sudo rm -r /var/lib/lodestar/chain-db

Teku

sudo rm -r /var/lib/teku/beacon

Nimbus

sudo rm -r /var/lib/nimbus/db

Lighthouse

sudo rm -r ~/.lighthouse/mainnet/beacon

Step 3: Ensure a checkpoint sync server is configured

• Below examples use the default checkpoint sync endpoint https://beaconstate.info

• Refer to https://eth-clients.github.io/checkpoint-sync-endpoints and pick another random state providers from the list, if desired.

• Do not trust any single checkpoint provider. Verify the state root and block root against multiple checkpoints to ensure you're on the correct chain.

Nimbus:

Run the following to start the checkpoint sync.

/usr/bin/nimbus_beacon_node trustedNodeSync \
--network=mainnet  \
--trusted-node-url=https://beaconstate.info \
--data-dir=/var/lib/nimbus \
--network=mainnet \
--backfill=false

When the nimbus checkpoint sync is complete, you'll see the following message:

Done, your beacon node is ready to serve you! Don't forget to check that you're on the canonical chain by comparing the checkpoint root with other online sources. See https://nimbus.guide/trusted-node-sync.html for more information.

Teku:

Edit your config file

sudo nano /etc/teku/teku.yaml

Ensure the following line is listed

initial-state: "https://beaconstate.info/eth/v2/debug/beacon/states/finalized"

To exit and save, press Ctrl + X, then Y, thenEnter.

Lighthouse:

Edit your service file

sudo nano /etc/systemd/system/beacon-chain.service

Ensure the following line is listed on your ExecStart line

--checkpoint-sync-url=https://beaconstate.info

To exit and save, press Ctrl + X, then Y, thenEnter.

Prysm:

Edit your service file

sudo nano /etc/systemd/system/beacon-chain.service

Ensure the following line is listed on your ExecStart line

--checkpoint-sync-url=https://beaconstate.info
--genesis-beacon-api-url=https://beaconstate.info

To exit and save, press Ctrl + X, then Y, thenEnter.

Lodestar:

Edit your service file

sudo nano /etc/systemd/system/beacon-chain.service

Ensure the following line is listed on your ExecStart line

--checkpointSyncUrl https://lodestar-mainnet.chainsafe.io

To exit and save, press Ctrl + X, then Y, thenEnter.

Step 4: Start consensus client

sudo systemctl daemon-reload
sudo systemctl restart beacon-chain

Step 5: Check the beacon chain logs and ensure sync is on right chain

Verify that you are on the correct chain by visiting https://eth-clients.github.io/checkpoint-sync-endpoints and selecting a different endpoint link. Verify that your log's are in agreement with the other endpoint's epoch / slot / state root / block root

View your logs:

journalctl -fu beacon-chain

Checkpoint sync should take no more than a few minutes to re-sync. Your execution client may take longer to catch up.

Congrats! You've successfully re-synced your consensus client.