This project prunes data from 'old' blocks from a CometBFT/Tendermint/Cosmos-sdk node.

Only the block, state and application databases are pruned.

Only goleveldb and pebbledb backends are supported.

How to use

Cosmprund works of a data directory that has the same structure of a normal cosmos-sdk/cometbft node. By default it will prune all but 10 blocks from cometbft, and all but 10 versions of application state.

# clone & build cosmprund repo
git clone https://github.com/ChorusOne/cosmprund/
cd cosmprund
make build

# stop your daemon/cosmovisor
sudo systemctl stop cosmovisor

# run cosmprund 
./build/cosmprund prune ~/.gaiad/data

Flags:

Flags:
      --cometbft             set to false you dont want to prune cometbft data (default true)
      --cosmos-sdk           set to false if using only with cometbft (default true)
      --force-compress-app   compress application.db even if it's larger than reasonable (10 GB)
                             The entire database needs to be read, so it will be slow
  -h, --help                 help for prune
  -b, --keep-blocks uint     set the amount of blocks to keep (default 100)
  -v, --keep-versions uint   set the amount of versions to keep in the application store (default 10)
      --run-gc               set to false to prevent a GC pass (default true)

Shortcomings

Not all stores are pruned, though usually block, state and application are the bulk of the data.

Within the application store, this tool currently only purges old states (s/ keys). Some chains store extra data here, and each chain required custom logic to prune it.

If you have a chain with a large application dir, you can try running statesync every once in a while to reduce it, alternatively, make an issue in this repo and we'll see if it can be pruned externally.

If no historical data is stored in application.db, it's usually pruned to a few (~50) MB. If there's significant historical data, then application.db will be large (20+GB); these cases are not supported yet, so using a large value for --compress-app-under-gb is not likely to achieve much.

Metadata

You can also use cosmprund db-info your-data-dir and you will get a JSON back in this form:

{"chain_id":"allora-testnet-1","initial_height":1,"last_block_height":3039285,"app_hash":"1CA3A44FC14A6D08137245F5FCB32275DD1150FEE76E3AD7F31FC5B388474854","last_block_time":"2025-03-17T17:06:31.620566697Z"}

which you can use to get a correct last_block_height for your snapshots

On speed

If you data directory is large, it will take a while to prune.

On our tests, a Berachain node with 150GB of data is pruned to ~50MB in ~10 minutes.

On size

Depending on the chain, results will vary; for many chains we see a (compressed) snapshot in the 10~300MB range.