If you followed the install instructions, you’ll be running everything from the SD card, leaving the four SATA slots for your network storage. If so, you are probably hitting the SD card really hard, as all logs will be written there.
Help avoid excessive writes by installing log2ram. This essentially reroutes your logs to RAM. Every day (or on shutdown), the logs will be written to the SD card. The obvious downside is that you’ll lose any unwritten logs during a power failure.
Installation is really easy:
echo "deb [signed-by=/usr/share/keyrings/azlux-archive-keyring.gpg] http://packages.azlux.fr/debian/ bullseye main" | sudo tee /etc/apt/sources.list.d/azlux.list
sudo wget -O /usr/share/keyrings/azlux-archive-keyring.gpg https://azlux.fr/repo.gpg
sudo apt update
sudo apt install log2ram
Then reboot and you are good to go. https://github.com/azlux/log2ram has manual install instructions if you prefer.