FAQ: Frequently Asked Questions and Reference Answers

Question

Inspired by this, here is a list of frequently asked questions grouped by topic:

Here are some provisional categories:

• What is Ethereum
• Getting Started
• Mining (Proof of Work)
• Proof of Stake
• Contract Development
• Clients and User Inferace / Experience
• Testing / Contract Deployment
• Systems built with/on/around the Ethereum platform

Please add/remove/re-order questions as you see fit...

Answer 1

Getting started

• What are the Ethereum disk space needs?
• How do I backup my ether accounts?
• How can I recover or reset a lost wallet password?
• How long does it take for the ethereum blockchain to synchronize?
• Ethereum Node Stuck, Can't Sync
• How do I buy Ethereum with USD?
• What is the recommended way to safely store Ether?

Answer 2

What is Ethereum

• How would I explain Ethereum to a non-technical friend?
• What are the differences between Bitcoin blockchain and Ethereum blockchain?
• What is the total supply of Ether?
• How does Lisk differ from Ethereum?
• What's the difference between proof of stake and proof of work?
• Why does Ethereum plan to move to Proof of Stake?
• What is "gas" and transaction fee in Ethereum?
• What is an uncle/ommer block?
• How is the address of an Ethereum contract computed?
• What is the difference between a transaction and a call?
• What is a DApp?
• Why don't Ethereum addresses have checksums?

Answer 3

Mining (Proof of Work)

• What's the best Hardware for Mining Ether?
• How to Mine Ether and use Ethereum on Windows?
• What are some good mining pools?
• How do I check my mining hashrate?
• When will the difficulty bomb make mining impossible?
• How to mine Ether on GNU + Linux?
• Is CPU mining even worth the Ether?
• What is the current DAG size? When do we expect to hit GPU limits?
• Why is the average block time 17 seconds?

proof-of-workminingmining-pools

Answer 4

Clients and UX

• Help with very slow mist sync
• What is Geth's "fast" sync, and why is it faster?
• How to import a plain private key into geth or Mist?
• How to backup mist wallets?
• How can I get a geth node to download the blockchain quickly?
• How to delete or reset the blockchain in geth? (OSX)
• What's the advantage of EthOS over Ubuntu or Windows mining?
• Where can I download the Mist browser? (NOT the Ethereum wallet)
• Common useful JavaScript snippets for geth

Clients:

go-ethereumparitypyethapp

GUIs:

metamaskmistparity

Answer 5

Contract Development

• Where can I find some Solidity / Smart Contract source code examples?
• How to call a contract method using the eth_call JSON-RPC API
• Upgradeable smart contracts
• How can I securely generate a random number in my smart contract?
• Can contracts pay the gas instead of the message sender?
• How can an Ethereum contract get data from a website?
• How can a contract run itself at a later time?
• Is there anything stopping me from using the ethereum blockchain as data storage?
• What is a recursive calling vulnerability?
• What OPCODES are available for the Ethereum EVM?
• Is it a good practice to log an event every time I throw in Solidity?

contract-developmentcontract-debuggingcontract-designeventsevm

High Level Languages

serpentsoliditylll

Compilers

compilationbrowser-soliditysolc

Contract Interface Development

• What is an ABI and why is it needed to interact with contracts?
• What is the difference between a transaction and a call?
• How to get contract internal transactions
• Is it a good practice to log an event every time I throw in Solidity?
• How do I parse the transaction receipt log with web3.js?
• How to call a contract method using the eth_call JSON-RPC API

abiweb3jsjson-rpc

Answer 6

Proof of Stake

• How does the Casper proof of stake algorithm work?
• When will Ethereum switch to Proof of Stake so miners can plan to prepare themselves?
• Why does Ethereum plan to move to Proof of Stake?
• What's the difference between proof of stake and proof of work?

proof-of-stake

Answer 7

Systems built on/with/around Ethereum

Ethereum Name Service

A distributed, extensible naming system based on the Ethereum blockchain.

• Is it possible to get a list of all active auctions on ENS?
• How can I bid in an ENS auction?

ens

File Retrieval: IPFS, Storj and Swarm

• What is the difference between Swarm and IPFS?
• What is Swarm and what is it used for?
• How can I store big files on the blockchain?
• How to access files hosted on swarm?
• How to add a file to IPFS using the API?

ipfsswarmstorj

The "The DAO"

• How do I convert my The DAO tokens into ethers using the withdrawal contract after the hard fork?
• How to withdraw Ether from The DAO?
• How do I convert my The DAO tokens into ethers on the Ethereum Classic chain?
• How do I get a refund for the amount I paid in excess of 1 ether to 100 The DAO tokens

the-dao

Answer 8

Testing

Simulated Node

testrpc

Private Testnet

• How do I set up a private ethereum network?

private-blockchain

Public Testnet

testnets