By far the most common scenario is people wanting to simply interact with the Ethereum network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn’t care about years-old historical data, so we can fast-sync quickly to the current state of the network. To do so:
Start geth in fast sync mode (default, can be changed with the --syncmode flag), causing it to download more data in exchange for avoiding processing the entire history of the Ethereum network, which is very CPU intensive.
Start up geth‘s built-in interactive JavaScript console, (via the trailing console subcommand) through which you can invoke all official web3 methods as well as geth‘s own management APIs. This tool is optional and if you leave it out you can always attach to an already running geth instance with geth attach.
Transitioning towards developers, if you’d like to play around with creating Ethereum contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the mordor test network with your node, which is fully equivalent to the main network, but with play-Ether only.
1
$geth--mordorconsole
The console subcommand has the exact same meaning as above and they are equally useful on the testnet too. Please see above for their explanations if you’ve skipped here.
Specifying the --mordor flag, however, will reconfigure your geth instance a bit:
Instead of using the default data directory (~/.ethereum on Linux for example), geth will nest itself one level deeper into a mordor subfolder (~/.ethereum/mordor on Linux). Note, on OSX and Linux this also means that attaching to a running testnet node requires the use of a custom endpoint since geth attach will try to attach to a production node endpoint by default. E.g. geth attach <datadir>/mordor/geth.ipc. Windows users are not affected by this.
Instead of connecting the main Ethereum network, the client will connect to the mordor’s test network, which uses different P2P bootnodes, different network IDs and genesis states.
Note
Although there are some internal protective measures to prevent transactions from crossing over between the classic network and test network, you should make sure to always use separate accounts for play-money and real-money. Unless you manually move accounts, geth will by default correctly separate the two networks and will not make any accounts available between them.*
$ geth --help
NAME:
geth - the ETC Core Go-Ethereum command line interface
Copyright 2013-2019 The go-ethereum Authors
USAGE:
geth [options] command [command options] [arguments...]
VERSION:
1.11.21-unstable
COMMANDS:
account Manage accounts
attach Start an interactive JavaScript environment (connect to node)
console Start an interactive JavaScript environment
copydb Create a local chain from a target chaindata folder
dump Dump a specific block from storage
dumpconfig Show configuration values
dumpgenesis Dumps genesis block JSON configuration to stdout
export Export blockchain into file
export-preimages Export the preimage database into an RLP stream
import Import a blockchain file
import-preimages Import the preimage database from an RLP stream
init Bootstrap and initialize a new genesis block
inspect Inspect the storage size for each type of data in the database
js Execute the specified JavaScript files
license Display license information
makecache Generate ethash verification cache (for testing)
makedag Generate ethash mining DAG (for testing)
removedb Remove blockchain and state databases
show-deprecated-flags Show flags that have been deprecated
version Print version numbers
version-check Checks (online) whether the current version suffers from any known security vulnerabilities
wallet Manage Ethereum presale wallets
help, h Shows a list of commands or help for one command
ETHEREUM OPTIONS:
--config value TOML configuration file
--datadir value Data directory for the databases and keystore (default: "/Users/ziogaschr/Library/Ethereum")
--datadir.ancient value Data directory for ancient chain segments (default = inside chaindata)
--ancient.rpc value Connect to a remote freezer via RPC. Value must an HTTP(S), WS(S), unix socket, or 'stdio' URL. Incompatible with --datadir.ancient
--keystore value Directory for the keystore (default = inside the datadir)
--nousb Disables monitoring for and managing USB hardware wallets
--pcscdpath value Path to the smartcard daemon (pcscd) socket file
--networkid value Explicitly set network id (integer)(For testnets: use --ropsten, --rinkeby, --goerli, --mordor, --yolov2 instead) (default: 1)
--classic Ethereum Classic network: pre-configured Ethereum Classic mainnet
--mordor Mordor network: Ethereum Classic's cross-client proof-of-work test network
--rinkeby Rinkeby network: pre-configured proof-of-authority test network
--goerli Görli network: pre-configured proof-of-authority test network
--rinkeby Rinkeby network: pre-configured proof-of-authority test network
--yolov2 YOLOv2 network: pre-configured proof-of-authority shortlived test network.
--mintme MintMe.com Coin mainnet: pre-configured MintMe.com Coin mainnet
--ropsten Ropsten network: pre-configured proof-of-work test network
--syncmode value Blockchain sync mode ("fast", "full", or "light") (default: fast)
--exitwhensynced Exits after block synchronisation completes
--gcmode value Blockchain garbage collection mode ("full", "archive") (default: "full")
--txlookuplimit value Number of recent blocks to maintain transactions index by-hash for (default = index all blocks) (default: 0)
--ethstats value Reporting URL of a ethstats service (nodename:secret@host:port)
--identity value Custom node name
--lightkdf Reduce key-derivation RAM & CPU usage at some expense of KDF strength
--whitelist value Comma separated block number-to-hash mappings to enforce (<number>=<hash>)
--ecbp1100 value Configure ECBP-1100 (MESS) block activation number (default: 18446744073709551615)
LIGHT CLIENT OPTIONS:
--light.serve value Maximum percentage of time allowed for serving LES requests (multi-threaded processing allows values over 100) (default: 0)
--light.ingress value Incoming bandwidth limit for serving light clients (kilobytes/sec, 0 = unlimited) (default: 0)
--light.egress value Outgoing bandwidth limit for serving light clients (kilobytes/sec, 0 = unlimited) (default: 0)
--light.maxpeers value Maximum number of light clients to serve, or light servers to attach to (default: 100)
--ulc.servers value List of trusted ultra-light servers
--ulc.fraction value Minimum % of trusted ultra-light servers required to announce a new head (default: 75)
--ulc.onlyannounce Ultra light server sends announcements only
--light.nopruning Disable ancient light chain data pruning
DEVELOPER CHAIN OPTIONS:
--dev Ephemeral proof-of-authority network with a pre-funded developer account, mining enabled
--dev.period value Block period for proof-of-authority network to use in developer mode (0 = mine only if transaction pending) (default: 0)
--dev.pow Ephemeral proof-of-work network with a pre-funded developer account, mining enabled
ETHASH OPTIONS:
--ethash.cachedir value Directory to store the ethash verification caches (default = inside the datadir)
--ethash.cachesinmem value Number of recent ethash caches to keep in memory (16MB each) (default: 2)
--ethash.cachesondisk value Number of recent ethash caches to keep on disk (16MB each) (default: 3)
--ethash.cacheslockmmap Lock memory maps of recent ethash caches
--ethash.dagdir value Directory to store the ethash mining DAGs (default: "/Users/ziogaschr/Library/Ethash")
--ethash.dagsinmem value Number of recent ethash mining DAGs to keep in memory (1+GB each) (default: 1)
--ethash.dagsondisk value Number of recent ethash mining DAGs to keep on disk (1+GB each) (default: 2)
--ethash.dagslockmmap Lock memory maps for recent ethash mining DAGs
TRANSACTION POOL OPTIONS:
--txpool.locals value Comma separated accounts to treat as locals (no flush, priority inclusion)
--txpool.nolocals Disables price exemptions for locally submitted transactions
--txpool.journal value Disk journal for local transaction to survive node restarts (default: "transactions.rlp")
--txpool.rejournal value Time interval to regenerate the local transaction journal (default: 1h0m0s)
--txpool.pricelimit value Minimum gas price limit to enforce for acceptance into the pool (default: 1)
--txpool.pricebump value Price bump percentage to replace an already existing transaction (default: 10)
--txpool.accountslots value Minimum number of executable transaction slots guaranteed per account (default: 16)
--txpool.globalslots value Maximum number of executable transaction slots for all accounts (default: 4096)
--txpool.accountqueue value Maximum number of non-executable transaction slots permitted per account (default: 64)
--txpool.globalqueue value Maximum number of non-executable transaction slots for all accounts (default: 1024)
--txpool.lifetime value Maximum amount of time non-executable transaction are queued (default: 3h0m0s)
PERFORMANCE TUNING OPTIONS:
--cache value Megabytes of memory allocated to internal caching (default = 4096 mainnet full node, 128 light mode) (default: 1024)
--cache.database value Percentage of cache memory allowance to use for database io (default: 50)
--cache.trie value Percentage of cache memory allowance to use for trie caching (default = 15% full mode, 30% archive mode) (default: 15)
--cache.trie.journal value Disk journal directory for trie cache to survive node restarts (default: "triecache")
--cache.trie.rejournal value Time interval to regenerate the trie cache journal (default: 1h0m0s)
--cache.gc value Percentage of cache memory allowance to use for trie pruning (default = 25% full mode, 0% archive mode) (default: 25)
--cache.snapshot value Percentage of cache memory allowance to use for snapshot caching (default = 10% full mode, 20% archive mode) (default: 10)
--cache.noprefetch Disable heuristic state prefetch during block import (less CPU and disk IO, more time waiting for data)
--cache.preimages Enable recording the SHA3/keccak preimages of trie keys (default: true)
ACCOUNT OPTIONS:
--unlock value Comma separated list of accounts to unlock
--password value Password file to use for non-interactive password input
--signer value External signer (url or path to ipc file)
--allow-insecure-unlock Allow insecure account unlocking when account-related RPCs are exposed by http
API AND CONSOLE OPTIONS:
--ipcdisable Disable the IPC-RPC server
--ipcpath value Filename for IPC socket/pipe within the datadir (explicit paths escape it)
--http Enable the HTTP-RPC server
--http.addr value HTTP-RPC server listening interface (default: "localhost")
--http.port value HTTP-RPC server listening port (default: 8545)
--http.api value API's offered over the HTTP-RPC interface
--http.corsdomain value Comma separated list of domains from which to accept cross origin requests (browser enforced)
--http.vhosts value Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (default: "localhost")
--ws Enable the WS-RPC server
--ws.addr value WS-RPC server listening interface (default: "localhost")
--ws.port value WS-RPC server listening port (default: 8546)
--ws.api value API's offered over the WS-RPC interface
--ws.origins value Origins from which to accept websockets requests
--graphql Enable GraphQL on the HTTP-RPC server. Note that GraphQL can only be started if an HTTP server is started as well.
--graphql.corsdomain value Comma separated list of domains from which to accept cross origin requests (browser enforced)
--graphql.vhosts value Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (default: "localhost")
--rpc.gascap value Sets a cap on gas that can be used in eth_call/estimateGas (0=infinite) (default: 25000000)
--rpc.txfeecap value Sets a cap on transaction fee (in ether) that can be sent via the RPC APIs (0 = no cap) (default: 1)
--jspath loadScript JavaScript root path for loadScript (default: ".")
--exec value Execute JavaScript statement
--preload value Comma separated list of JavaScript files to preload into the console
NETWORKING OPTIONS:
--bootnodes value Comma separated enode URLs for P2P discovery bootstrap
--bootnodesv4 value Comma separated enode URLs for P2P v4 discovery bootstrap (light server, full nodes) (deprecated, use --bootnodes)
--bootnodesv5 value Comma separated enode URLs for P2P v5 discovery bootstrap (light server, light nodes) (deprecated, use --bootnodes)
--discovery.dns value Sets DNS discovery entry points (use "" to disable DNS)
--eth.protocols value Sets the Ethereum Protocol versions (65|64|63) (default = 65,64,63 first is primary)
--port value Network listening port (default: 30303)
--maxpeers value Maximum number of network peers (network disabled if set to 0) (default: 50)
--maxpendpeers value Maximum number of pending connection attempts (defaults used if set to 0) (default: 0)
--nat value NAT port mapping mechanism (any|none|upnp|pmp|extip:<IP>) (default: "any")
--nodiscover Disables the peer discovery mechanism (manual peer addition)
--v5disc Enables the experimental RLPx V5 (Topic Discovery) mechanism
--netrestrict value Restricts network communication to the given IP networks (CIDR masks)
--nodekey value P2P node key file
--nodekeyhex value P2P node key as hex (for testing)
MINER OPTIONS:
--mine Enable mining
--miner.threads value Number of CPU threads to use for mining (default: 0)
--miner.notify value Comma separated HTTP URL list to notify of new work packages
--miner.gasprice value Minimum gas price for mining a transaction (default: 1000000000)
--miner.gastarget value Target gas floor for mined blocks (default: 8000000)
--miner.gaslimit value Target gas ceiling for mined blocks (default: 8000000)
--miner.etherbase value Public address for block mining rewards (default = first account) (default: "0")
--miner.extradata value Block extra data set by the miner (default = client version)
--miner.recommit value Time interval to recreate the block being mined (default: 3s)
--miner.noverify Disable remote sealing verification
GAS PRICE ORACLE OPTIONS:
--gpo.blocks value Number of recent blocks to check for gas prices (default: 20)
--gpo.percentile value Suggested gas price is the given percentile of a set of recent transaction gas prices (default: 60)
--gpo.maxprice value Maximum gas price will be recommended by gpo (default: 500000000000)
VIRTUAL MACHINE OPTIONS:
--vmdebug Record information useful for VM and contract debugging
--vm.evm value External EVM configuration (default = built-in interpreter)
--vm.ewasm value External ewasm configuration (default = built-in interpreter)
LOGGING AND DEBUGGING OPTIONS:
--fakepow Disables proof-of-work verification
--fakepow.poisson Disables proof-of-work verification and adds mining delay (Poisson) based on --miner.threads
--nocompaction Disables db compaction after import
--verbosity value Logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=debug, 5=detail (default: 3)
--vmodule value Per-module verbosity: comma-separated list of <pattern>=<level> (e.g. eth/*=5,p2p=4)
--backtrace value Request a stack trace at a specific logging statement (e.g. "block.go:271")
--debug Prepends log messages with call-site location (file and line number)
--pprof Enable the pprof HTTP server
--pprof.addr value pprof HTTP server listening interface (default: "127.0.0.1")
--pprof.port value pprof HTTP server listening port (default: 6060)
--pprof.memprofilerate value Turn on memory profiling with the given rate (default: 524288)
--pprof.blockprofilerate value Turn on block profiling with the given rate (default: 0)
--pprof.cpuprofile value Write CPU profile to the given file
--trace value Write execution trace to the given file
METRICS AND STATS OPTIONS:
--metrics Enable metrics collection and reporting
--metrics.expensive Enable expensive metrics collection and reporting
--metrics.addr value Enable stand-alone metrics HTTP server listening interface (default: "127.0.0.1")
--metrics.port value Metrics HTTP server listening port (default: 6060)
--metrics.influxdb Enable metrics export/push to an external InfluxDB database
--metrics.influxdb.endpoint value InfluxDB API endpoint to report metrics to (default: "http://localhost:8086")
--metrics.influxdb.database value InfluxDB database name to push reported metrics to (default: "geth")
--metrics.influxdb.username value Username to authorize access to the database (default: "test")
--metrics.influxdb.password value Password to authorize access to the database (default: "test")
--metrics.influxdb.tags value Comma-separated InfluxDB tags (key/values) attached to all measurements (default: "host=localhost")
WHISPER (deprecated) OPTIONS:
--shh Enable Whisper
--shh.maxmessagesize value Max message size accepted (default: 1048576)
--shh.pow value Minimum POW accepted (default: 0.2)
--shh.restrict-light Restrict connection between two whisper light clients
ALIASED (deprecated) OPTIONS:
--rpc Enable the HTTP-RPC server (deprecated, use --http)
--rpcaddr value HTTP-RPC server listening interface (deprecated, use --http.addr) (default: "localhost")
--rpcport value HTTP-RPC server listening port (deprecated, use --http.port) (default: 8545)
--rpccorsdomain value Comma separated list of domains from which to accept cross origin requests (browser enforced) (deprecated, use --http.corsdomain)
--rpcvhosts value Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (deprecated, use --http.vhosts) (default: "localhost")
--rpcapi value API's offered over the HTTP-RPC interface (deprecated, use --http.api)
--wsaddr value WS-RPC server listening interface (deprecated, use --ws.addr) (default: "localhost")
--wsport value WS-RPC server listening port (deprecated, use --ws.port) (default: 8546)
--wsorigins value Origins from which to accept websockets requests (deprecated, use --ws.origins)
--wsapi value API's offered over the WS-RPC interface (deprecated, use --ws.api)
--gpoblocks value Number of recent blocks to check for gas prices (deprecated, use --gpo.blocks) (default: 20)
--gpopercentile value Suggested gas price is the given percentile of a set of recent transaction gas prices (deprecated, use --gpo.percentile) (default: 60)
--graphql.addr value GraphQL server listening interface (deprecated, graphql can only be enabled on the HTTP-RPC server endpoint, use --graphql)
--graphql.port value GraphQL server listening port (deprecated, graphql can only be enabled on the HTTP-RPC server endpoint, use --graphql) (default: 8545)
--pprofport value pprof HTTP server listening port (deprecated, use --pprof.port) (default: 6060)
--pprofaddr value pprof HTTP server listening interface (deprecated, use --pprof.addr) (default: "127.0.0.1")
--memprofilerate value Turn on memory profiling with the given rate (deprecated, use --pprof.memprofilerate) (default: 524288)
--blockprofilerate value Turn on block profiling with the given rate (deprecated, use --pprof.blockprofilerate) (default: 0)
--cpuprofile value Write CPU profile to the given file (deprecated, use --pprof.cpuprofile)
MISC OPTIONS:
--snapshot Enables snapshot-database mode -- experimental work in progress feature
--help, -h show help
COPYRIGHT:
Copyright 2013-2020 The core-geth and go-ethereum Authors