## I would like to run multiple Geth instances but got the error "Fatal: blockchain db err: resource temporarily unavailable". {#multiple-geth-instances}
Geth uses a datadir to store the blockchain, accounts and some additional information. This directory cannot be shared between running instances. If you would like to run multiple instances follow [these](/docs/developers/geth-developer/private-network) instructions.
Geth uses a datadir to store the blockchain, accounts and some additional information. This directory cannot be shared between running instances. If you would like to run multiple instances follow [these](/docs/fundamentals/private-network) instructions.
## When I try to use the --password command line flag, I get the error "Could not decrypt key with given passphrase" but the password is correct. Why does this error appear? {#could-not-decrypt-key}
@ -24,4 +24,4 @@ Note also that there is a page explaining common log messages that are often que
- [Pruning](/docs/fundamentals/pruning): read about Geth's data pruning options
- [Private networks](/docs/fundamentals/private-network): learn hoe to set up a private network of multiple Geth nodes
- [Light clients](/docs/fundamentals/les): read about Geth's light mode.
- [Mining](/docs/fundamentals/mining): read about the minign algorithms Geth used to use to secure Ethereum before the network switched to proof-of-stake.
- [Mining](/docs/fundamentals/mining): read about the minign algorithms Geth used to use to secure Ethereum before the network switched to proof-of-stake.
description: Guide to connecting Geth to a peer-to-peer network
---
The default behaviour for Geth is to connect to Ethereum Mainnet. However, Geth can also connect to public testnets, [private networks](/docs/developers/geth-developer/private-network) and [local testnets](/docs/developers/geth-developer/dev-mode). For convenience, the two public testnets with long term support, Goerli and Sepolia, have their own command line flag. Geth can connect to these testnets simply by passing:
The default behaviour for Geth is to connect to Ethereum Mainnet. However, Geth can also connect to public testnets, [private networks](/docs/fundamentals/private-network) and [local testnets](/docs/developers/geth-developer/dev-mode). For convenience, the two public testnets with long term support, Goerli and Sepolia, have their own command line flag. Geth can connect to these testnets simply by passing:
- `--goerli`, Goerli proof-of-authority test network
- `--sepolia` Sepolia proof-of-work test network
@ -106,7 +106,7 @@ The `admin` module also includes functions for gathering information about the l
## Custom Networks {#custom-networks}
It is often useful for developers to connect to private test networks rather than public testnets or Ethereum mainnet. These sandbox environments allow block creation without competing against other miners, easy minting of test ether and give freedom to break things without real-world consequences. A private network is started by providing a value to `--networkid` that is not used by any other existing public network ([Chainlist](https://chainlist.org)) and creating a custom `genesis.json` file. Detailed instructions for this are available on the [Private Networks page](/docs/developers/geth-developer/private-network).
It is often useful for developers to connect to private test networks rather than public testnets or Ethereum mainnet. These sandbox environments allow block creation without competing against other miners, easy minting of test ether and give freedom to break things without real-world consequences. A private network is started by providing a value to `--networkid` that is not used by any other existing public network ([Chainlist](https://chainlist.org)) and creating a custom `genesis.json` file. Detailed instructions for this are available on the [Private Networks page](/docs/fundamentals/private-network).
@ -25,4 +25,4 @@ Geth has built-in account management tools. However, Clef is recommended as an e
## Other security considerations {#other-security}
Even with a perfectly secure node, users can still be manipulated by attackers into exposing security weaknesses or inadvertently interact with insecure smart contracts. For an overview, please see the Ethereum [security best practise webpage](https://ethereum.org/en/security) and this introduction to [smart contract security](https://ethereum.org/en/developers/docs/smart-contracts/security).
Even with a perfectly secure node, users can still be manipulated by attackers into exposing security weaknesses or inadvertently interact with insecure smart contracts. For an overview, please see the Ethereum [security best practice webpage](https://ethereum.org/en/security) and this introduction to [smart contract security](https://ethereum.org/en/developers/docs/smart-contracts/security).
@ -11,7 +11,7 @@ Clef provides a way to safely circumvent `--unlock` while maintaining a enough a
## Prerequisites {#prerequisites}
It is useful to have basic knowledge of private networks and Clef. These topics are covered on our [private networks](/docs/developers/geth-developer/private-network) and [Introduction to Clef](/docs/tools/clef/introduction) pages.
It is useful to have basic knowledge of private networks and Clef. These topics are covered on our [private networks](/docs/fundamentals/private-network) and [Introduction to Clef](/docs/tools/clef/introduction) pages.
## Prepping a Clique network {#prepping-clique-network}
Paul Wackerow
2 years ago