hotdisk

content/5.nonsense/2.bash/4.hotdisk.md

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+---
+navigation: true
+title: HotDisk
+main:
+  fluid: false
+---
+:ellipsis{left=0px width=40rem top=10rem blur=140px}
+
+# HotDisk
+---
+
+When you have a NAS with several drives sitting in a laundry room, temperatures can quickly rise.  
+Hard drives are very sensitive to heat and can suffer serious damage if they exceed a certain temperature threshold for too long.  
+After a particularly hot summer that caused a few cold sweats while monitoring my drives’ temperatures, I started looking for a way to automatically shut down the server when disk temperatures stay above their safe limit for an extended period.
+
+Since I couldn’t find a convincing solution, I decided to build my own.
+
+- The script reads SMART temperature data from all SATA drives every minute.  
+- It counts the number of consecutive minutes the temperature stays above or below the threshold.  
+- It sends Discord notifications if the threshold is exceeded or when the temperature cools down.  
+- It triggers a system shutdown if the temperature stays above the limit for the configured duration.  
+- It logs all temperatures and counter states, and automatically rotates log files.
+
+While I was at it, I also added an installation script that installs the main script, makes it executable, creates a systemd service and timer, and enables them automatically.  
+The installer also lets you configure various parameters:
+
+| Variable              | Description                                                                 | Default Value                                 |
+|-----------------------|------------------------------------------------------------------------------|-----------------------------------------------|
+| `MAX_TEMP`            | Maximum allowed temperature (°C) before the shutdown countdown starts        | `60`                                          |
+| `HOT_DURATION`        | Consecutive minutes above `MAX_TEMP` before shutdown                        | `5`                                           |
+| `COOL_RESET_DURATION` | Consecutive minutes below `MAX_TEMP` to reset all counters                  | `5`                                           |
+| `LOG_FILE`            | Path to the main log file                                                   | `/var/log/hdd_temp_monitor.log`               |
+| `LOG_ROTATE_COUNT`    | Number of log files to keep                                                 | `7`                                           |
+| `LOG_ROTATE_PERIOD`   | Log rotation period (`daily` or `weekly`)                                   | `daily`                                       |
+| `DISCORD_WEBHOOK`     | Discord webhook URL for notifications                                       | _Required_                                   |
+
+It also runs another script that configures **logrotate** with the parameters defined above.  
+Finally, the installer can even be executed directly via a simple `curl` command followed by one last setup script — perfect for the laziest of us.
+
+I also had to handle several tricky cases: running as root without sudo, using sudo directly, running as a non-sudo user, missing dependencies, permission issues, file creation errors, disk data reading errors, and more.  
+
+Concurrent access to the status file also had to be managed carefully.
+
+More details are available directly on the repository:
+
+::card
+#title
+📜 __HotDisk__
+#description
+[Keep your drives cool!](https://git.djeex.fr/Djeex/hotdisk)
+::