Documentation https://github.com/ethereum/go-ethereum/wiki/Private-network
To create a database that uses this genesis block, run the following command. This will import and set the canonical genesis block for your chain.
geth --datadir ./dataDir init genesis.json
geth --datadir ./dataDir --networkid 15 --rpc --rpccorsdomain "*" console 2>> geth.log
tail -f geth.log