5 minute read

SD card wear caused by running Home Assistant on a Raspberry Pi seems to be a very commonly-debated topic on the Home Assistant forums. I’ve personally lost more than one SD card to excessive reads and writes, ultimately leading to system failure. To help mitigate the issue, I switched over to pushing log data to a remote database but found that Home Assistant becomes very unstable if the remote server becomes unavailable. This article documents the process of setting up a Raspberry Pi, Docker, log2ram, and Home Assistant (hass.io).

Installing and Configuring the Raspberry-Pi-OS

Installing Raspberry-Pi-OS

The Raspberry Pi foundation documentation does a good job describing how to flash an image to the SD card and get your Pi up-and-running. You can find the official guide here. You’ll want to use the “Raspberry Pi OS (32-bit) Lite” image for this application link.

I also recommend enabling ssh on your Raspberry Pi before booting it for the first time. You can do this by creating an empty file in the BOOTfolder on your SD card.

  • Windows Users: Create a .txt file in the BOOT directory on your SD card and rename it to ssh without an extension. You may have to change your folder settings to show extensions on known filetypes link.
  • Linux Users: You can either do something similar to what I mentioned for Windows users, or if you’re handy with the terminal you can navigate to the BOOTdirectory and type: touch ssh

The Raspberry Pi foundation also has a tutorial on configuring the Raspberry Pi for headless operation link.

Configuring Raspberry-Pi-OS

Once you’ve connected to the Pi (the default login information is: U:pi P:raspberry), run sudo raspi-config to bring up the configuration window.

  1. Select the first option (Change User Password) and set a new password.
  2. Select the fourth option (Localisation Options) and select Change Time Zone. Home Assistant needs to know your current time zone so that logs and other things behind-the-scenes work correctly.
  3. Feel free to adjust other settings as necessary. Once finished, select Finish and allow the Pi to reboot.

Once the Pi reboots, enter the following command to update the OS.

sudo apt update && sudo apt upgrade -y && sudo apt autoremove -y

Installing Docker

Installing Docker is very straightforward. Enter the following commands in the order shown:

Install Docker

curl -sSL https://get.docker.com | sh

Add the “pi” User to the “docker” group

This command is necessary for the “pi” user to interface with docker containers.

sudo usermod -aG docker pi

After executing this command, reboot the Pi.

Test the Docker installation

docker run hello-world

If this command shows you a “hello world” message, then docker should be working correctly.

Install Docker dependencies

sudo apt-get install -y libffi-dev libssl-dev
sudo apt-get install -y python3 python3-pip

These dependencies are only required for Docker to run. I also use docker-compose to manage other containers outside of hass.io, so executing the command below will install docker-compose.

sudo pip3 -v install docker-compose

Docker should now be ready!

Installing the Supervisor and Dependencies

Installing the hass.io supervisor outside of the installer provided by the Home Assistant team is unsupported. All this means is that if you run into any issues, the Home Assistant developers won’t be able to (or want to) help.

The Home Assistant development team provides an install script for setting up the supervisor (hass.io) on a system outside of the hass.io image. The script is hosted on the project site here.

A few dependencies need to be installed, and a service needs to be disabled before you can run the script. Execute the commands below to get things set up.

sudo -i

apt-get install -y software-properties-common apparmor-utils apt-transport-https avahi-daemon ca-certificates curl dbus jq network-manager

systemctl disable ModemManager

systemctl stop ModemManager

Once everything is installed and configured, issue the command below, substituting MY_MACHINE with your Raspberry Pi model (supported machine types shown below).

curl -sL https://raw.githubusercontent.com/home-assistant/supervised-installer/master/installer.sh | bash -s -- -m MY_MACHINE

Note: The script supports 64-bit installations, but Raspberry-Pi-OS is a 32-bit OS!

Home Assistant (hass.io) should be available a few minutes after the script is finished. Use the command below to watch the Docker container start up. You can exit the log monitor by pressing Ctrl + C.

docker logs hassio_supervisor -f

Installing and Configuring log2ram

log2ram creates a mount point in RAM where applications can write log data instead of writing directly to the SD card. Data logged in RAM is then periodically copied to the SD card on a predetermined schedule. The log2ram project is hosted on GitHub and has a list of commands needed to install it. Once you’ve rebooted your Pi, edit the log2ram configuration file located at etc/log2ram.conf

I changed the default size and log location to what’s shown below.


If you ran the hass.io supervisor installation script with the default path settings, this path should also be valid for your installation.

Configuring hass.io to use log2ram

We need to modify a few configuration files and create a symlink before hass.io is ready to use.

Navigate to /usr/share/hassio/homeassistant and create a new directory for your logs (sudo is required for all of these commands).

sudo mkdir logs

Add the text below to your configuration.yaml file using a text editor or the web interface. This command tells Home Assistant to write the SQLite database to the logs/ folder in the Home Assistant configuration directory. Note: This path is meant to be relative! Remember, Home Assistant is running in a Docker container!

  db_url: sqlite:///logs/home-assistant_v2.db

Once you’ve saved and closed the file, navigate to Configuration > General > Server Controls and stop the server. Be sure to wait a minute or two for Home Assistant to finish writing to the database and log files.

Move the database and log files into the logs/ directory.

cd /usr/share/hassio/homeassistant/
sudo mv home-assistant.log logs/
sudo mv home-assistant_v2.db logs/

Create a symlink to the Home Assistant log file using the command below.

cd /usr/share/hassio/homeassistant/
sudo ln -s logs/home-assistant.log home-assistant.log

Start log2ram to have it initialize the directories.

sudo log2ram start

Executing this command should’ve created a new folder in the homeassistant/ directory called hdd.logs. This directory is where log2ram will write the logs as per the schedule you configured earlier. You should have also seen the rsync output detect and write the two log files we just moved along with log2ram.log.

sent 4,736,778 bytes  received 46,093 bytes  9,565,742.00 bytes/sec
total size is 18,661,461  speedup is 3.90
building file list ... done


That’s it! Once you reboot your Pi, your logs should now be written to RAM and periodically backed up to the SD card!