预挖矿
如果希望在指定的账户中有一定的eth供测试，可以先新建一个账户，将这个账户放到创世区块的配置文件中
root@iZ2ze1lsoerlt75gu9joguZ:/var/eth# ./geth --datadir private_data/ account new
WARN [09-29|12:01:31] No etherbase set and no accounts found as default
Your new account is locked with a password. Please give a password. Do not forget this password.
Passphrase:
Repeat passphrase:
Address: {7babfbc6938cf9968d6b106e8618328d1478e79e}
这里要注意的是，指定私有数据目录，后面的创世区块命名也要一致
创世区块配置
{
"config": {
"chainId": 15,
"homesteadBlock": 0,
"eip155Block": 0,
"eip158Block": 0
},
"difficulty": "0x4000",
"gasLimit": "2100000",
"alloc": {
"7babfbc6938cf9968d6b106e8618328d1478e79e": { "balance": "10000000000000000000000" }
}
}
alloc非必须字段，如果不预挖矿，可不要，另外balance的单位是wei，1个以太币=10^18wei，后面要加足够的0，然后运行初始化命令
root@iZ2ze1lsoerlt75gu9joguZ:/var/eth# ./geth --datadir private_data/ init genesis.json
INFO [09-29|12:04:17] Allocated cache and file handles database=/var/eth/private_data/geth/chaindata cache=16 handles=16
INFO [09-29|12:04:17] Writing custom genesis block
INFO [09-29|12:04:17] Successfully wrote genesis state database=chaindata hash=5d1258…d0deb6
INFO [09-29|12:04:17] Allocated cache and file handles database=/var/eth/private_data/geth/lightchaindata cache=16 handles=16
INFO [09-29|12:04:17] Writing custom genesis block
INFO [09-29|12:04:17] Successfully wrote genesis state database=lightchaindata hash=5d1258…d0deb6
看到success，也就OK了，现在看看账户中余额是不是有了余额，进入console
root@iZ2ze1lsoerlt75gu9joguZ:/var/eth# ./geth --datadir private_data/ console
> web3.fromWei(eth.getBalance(eth.accounts[0]),'ether')
10000
嗯，给定账户中有一万个币了，想想是千万富翁了。。。
