solana/book/src/running-validator/validator-start.md

Starting a Validator

Configure Solana CLI

The solana cli includes get and set configuration commands to automatically set the --url argument for cli commands. For example:

solana config set --url http://devnet.solana.com:8899

(You can always override the set configuration by explicitly passing the --url argument with a command, eg: solana --url http://beta.devnet.solana.com:8899 balance)

Confirm The Testnet Is Reachable

Before attaching a validator node, sanity check that the cluster is accessible to your machine by fetching the transaction count:

solana transaction-count

Inspect the network explorer at https://explorer.solana.com/ for activity.

View the metrics dashboard for more detail on cluster activity.

Confirm your Installation

Try running following command to join the gossip network and view all the other nodes in the cluster:

solana-gossip spy --entrypoint devnet.solana.com:8001
# Press ^C to exit

Enabling CUDA

If your machine has a GPU with CUDA installed Linux-only currently, include the --cuda argument to solana-validator.

When your validator is started look for the following log message to indicate that CUDA is enabled: "[<timestamp> solana::validator] CUDA is enabled"

Tune System

For Linux validators, the solana repo includes a daemon to adjust system settings to optimize performance (namely by increasing the OS UDP buffer limits, and scheduling PoH with realtime policy).

The daemon (solana-sys-tuner) is included in the solana binary release.

To run it:

sudo solana-sys-tuner --user $(whoami) > sys-tuner.log 2>&1 &

Generate identity

Create an identity keypair for your validator by running:

solana-keygen new -o ~/validator-keypair.json

The identity public key can now be viewed by running:

solana-keygen pubkey ~/validator-keypair.json

Note: The "validator-keypair.json” file is also your ed25519 private key.

Your validator identity keypair uniquely identifies your validator within the network. It is crucial to back-up this information.

If you don’t back up this information, you WILL NOT BE ABLE TO RECOVER YOUR VALIDATOR if you lose access to it. If this happens, YOU WILL LOSE YOUR ALLOCATION OF LAMPORTS TOO.

To back-up your validator identify keypair, back-up your "validator-keypair.json” file to a secure location.

Vanity Keypair

You can generate a custom vanity keypair using solana-keygen. For instance:

solana-keygen grind --starts-with e1v1s

Depending on the string requested, it may take days to find a match...

More Solana CLI Configuration

Now that you have a keypair, set the solana configuration to use your validator keypair for all following commands:

solana config set --keypair ~/validator-keypair.json

You should see the following output:

Wallet Config Updated: /home/solana/.config/solana/wallet/config.yml
* url: http://devnet.solana.com:8899
* keypair: /home/solana/validator-keypair.json

Airdrop & Check Validator Balance

Airdrop yourself some SOL to get started:

solana airdrop 1000

To view your current balance:

solana balance

Or to see in finer detail:

solana balance --lamports

Read more about the difference between SOL and lamports here.

Create Vote Account

If you haven’t already done so, create a vote-account keypair and create the vote account on the network. If you have completed this step, you should see the “validator-vote-keypair.json” in your Solana runtime directory:

solana-keygen new -o ~/validator-vote-keypair.json

Create your vote account on the blockchain:

solana create-vote-account ~/validator-vote-keypair.json ~/validator-keypair.json

Connect Your Validator

Connect to a testnet cluster by running:

solana-validator --identity-keypair ~/validator-keypair.json --voting-keypair ~/validator-vote-keypair.json \
    --ledger ~/validator-ledger --rpc-port 8899 --entrypoint devnet.solana.com:8001 \
    --limit-ledger-size

To force validator logging to the console add a --log - argument, otherwise the validator will automatically log to a file.

Confirm your validator connected to the network by opening a new terminal and running:

solana-gossip spy --entrypoint devnet.solana.com:8001

If your validator is connected, its public key and IP address will appear in the list.

Controlling local network port allocation

By default the validator will dynamically select available network ports in the 8000-10000 range, and may be overridden with --dynamic-port-range. For example, solana-validator --dynamic-port-range 11000-11010 ... will restrict the validator to ports 11000-11011.

Limiting ledger size to conserve disk space

The --limit-ledger-size arg will instruct the validator to only retain the last couple hours of ledger. To retain the full ledger, simply remove that arg.