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System configuration

You are now on the command line of your own Bitcoin node. Let’s start with the configuration.

Table of contents

  1. Add users
  2. Check USB3 drive performance
  3. System update
  4. Data directory
  5. Increase swap file size

Add users

We will use the primary user “admin” instead of “pi” to make this guide more universal.

  • Instruct your shell (the command line) to always use the default language settings. This prevents annoying error messages

    $ echo "export LC_ALL=C" >> ~/.bashrc
    $ source ~/.bashrc
  • Create a new user called “admin” with your password [A]

    $ sudo adduser --gecos "" admin
  • Make this new user a superuser by adding it to the “sudo” group

    $ sudo adduser admin sudo

The Bitcoin Core application will run in the background (as a “daemon”) and use the separate user “bitcoin” for security reasons. This user does not have admin rights and cannot change the system configuration.

  • Create the user “bitcoin”

    $ sudo adduser --gecos "" --disabled-password bitcoin
  • Add the user “admin” to the group “bitcoin” as well

    $ sudo adduser admin bitcoin

Check USB3 drive performance

A performant USB3 drive is essential for your node. The Raspberry Pi 4 supports these out of the box, but is a bit picky. Some USB3 adapters for external drives are not compatible and need a workaround to be usable.

Let’s check if your drive works well as-is, or if additional configuration is needed.

  • Install the software to measure the performance of your drive

    $ sudo apt update
    $ sudo apt install hdparm
  • Your external disk should be connected as /dev/sda. Check if this is the case by listing the names of connected block devices

    $ lsblk -pli
  • Measure the speed of your external drive

    $ sudo hdparm -t --direct /dev/sda
    > Timing O_DIRECT disk reads: 932 MB in  3.00 seconds = 310.23 MB/sec

If the measured speed is more than 50 MB/s, you’re good, no further action needed.

If the speed of your USB3 drive is not acceptable, we need to configure the USB driver to ignore the UAS interface.

Check the Fix bad USB3 performance entry in the Troubleshooting guide to learn how.

System update

Exit your current “pi” user session and exit SSH

$ exit

It is important to keep the system up-to-date with security patches and application updates. The “Advanced Packaging Tool” (apt) makes this easy.

  • Log in again using SSH, but now with the user “admin” and your password [A]

    $ ssh admin@raspibolt.local

    To change the system configuration and files that don’t belong to the “admin”, you have to prefix commands with sudo. You will be prompted to enter your admin password from time to time for increased security.

  • Instruct your shell to always use the default language settings. This prevents annoying error messages.

    $ echo "export LC_ALL=C" >> ~/.bashrc
    $ source ~/.bashrc
  • Update the operating system and all installed software packages

    $ sudo apt update
    $ sudo apt full-upgrade

    💡 Do this regularly every few months to get security-related updates.

  • Make sure that all necessary software packages are installed:

    $ sudo apt install wget curl gpg git htop jq qrencode --install-recommends

Data directory

We’ll store all application data in the dedicated directory /data/. This allows for better security because it’s not inside any user’s home directory. Additionally, it’s easier to move that directory somewhere else, for instance to a separate drive, as you can just mount any storage option to /data/.

  • Create the directory and make user “bitcoin” its owner

    $ sudo mkdir /data
    $ sudo chown bitcoin:bitcoin /data

Increase swap file size

The swap file acts as slower memory and is essential for system stability. The standard size of 100M is way too small.

  • Edit the configuration file and comment the entry CONF_SWAPSIZE by placing a # in front of it. Save and exit.

    $ sudo nano /etc/dphys-swapfile
    # comment or delete the CONF_SWAPSIZE line. It will then be created dynamically
  • Recreate and activate new swapfile

    $ sudo dphys-swapfile install
    $ sudo systemctl restart dphys-swapfile.service

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