geth node on ubuntu setup question

Question

To run a node on my vps,

1. --rpccorsdomain "mydomain.com" and set maxconnection, can be set at the same time so that only my own website can send rpc call for security, also I use max connection to limit the bandwidth?
2. What is the correct geth command for init node and start node? Do I still need the file CustomGenesis.json?
3. Usually how big the node is? and how long to download?

also, I created some demo account by script lightwallet, I cannot find which one is the private keys from the keystore object:

{"salt":"FneDYAPZOTF4f4Gdylm3wMlJv7QLMcvGB1+upxjQvE8=","hdPathString":"m/0'/0'/0'","encSeed":{"encStr":"ruohZV2xykidwTOmM0GtijnhaMGP2dMSUGdBJ/Teh8KIO4JvTa5cOgKxpYEoKKVmZwzzpzfsAw3XehDlNUYnYwE+J6jgB2N8JGxbBVufz5IMMjS0QOw0y8ILf35TMxbRcQFkEstcDACfOWrn0B98xzuvnAwNmh4lC0iLSTm8SV8t/HQn/hbfbQ==","nonce":"Ia3VbewxYFRHr1HfFJgGl4VElo80xGE9"},"encHdRootPriv":{"encStr":"nxB7ElsU/VIP7fSHmGwIjPrEEC2HY7XFbnrIW1+NPrpmBr/LduWwR7Rc7l2BcK5P3yGh6ZtTo+Z+aGyuH4smZnFLM+cwKqMhMZGQrkZxeeIEUjosLqhs2iwAaF8BHW5Pb4zzfE0DeX2UuRoJAE70KrdE0Ed22u9v1tv2zF6Clg==","nonce":"BTYyIsI1Oq4tGXBOl4Qvok7E0DXbxa3o"},"version":3,"hdIndex":3,"encPrivKeys":{"14ad302bf56a84cc48a553fb83f703a996f184c0":{"key":"BfZzyE1PsJ14f4ONi7CcBkNmWBx71QlDeNFj8MIBXzv9plyRUka/GaxMzKr60Y8D","nonce":"NcImsJ2MbIjZJEIK8Ho6p3SgawFJk/LR"},"648c78407bf7392de7153515e7b2714cec103709":{"key":"lPpTSyRrIxi16lRiZMIlk2CzPctYTUkZOPkmMNz3U5Qus3zko0SwjLRKo9iKAlLf","nonce":"+JhVJtdKKhnvAvdPEeFYem5IBIBsFZpx"},"cf69e4be058fbdc03f921654cc14b865c9c8cbbe":{"key":"8KVDtJ6cQZ39XKwJqB3QfwZPbJjw9a6JA2gVnHQOdOqMaIGxfgsQYg8N9HY9DLQX","nonce":"7yF0LSgUB+88gaC/kGK+1TkFrSE63WEc"}},"addresses":["14ad302bf56a84cc48a553fb83f703a996f184c0","648c78407bf7392de7153515e7b2714cec103709","cf69e4be058fbdc03f921654cc14b865c9c8cbbe"]}

How can I find the private key for each account? This is just for testing

Answer 1

You can use this command to initialize your private node and allow rpc connection to specific port at the same time.

geth --datadir ./datadir_new --networkid 2018 --port 30303 --rpc --rpcapi “db,personal,eth,net,web3,debug” --rpccorsdomain=”*” --rpcaddr=”localhost” --rpcport 8545 console

Answer 2

1. Yes, you can use these two flags at the same time
2. The commands can vary depending if you're setting up for a public network or private network. I'll assume you want a to connect to mainnet. So pass the --mainnet flag and it will configure everything for you, network ID, genesis, and bootnodes. Same can be done with --rinkeby and other known networks.
3. The amount of storage needed by a node varies depending on the network and the synchronization mode. See this page https://etherscan.io/chart2/chaindatasizefast