System monitoring & logs
SD Migrator continuously monitors the Pi’s temperatures, power supply and fan. You can spot critical states immediately by their coloured fields, and if the device overheats, it shuts down in good time and in an orderly way.
The status display
The readings are updated every 2 seconds. Where you find them depends on the device:
- Desktop: in the header
- Tablet in landscape: in the left sidebar
The display shows:
- CPU temperature and NVMe temperature
- Input voltage
- Power (W) and current of the Pi at 5 V. These values apply only to the Pi itself. Converter losses and connected devices (USB devices, NVMe HAT) are not included.
- Fan speed
- with a UPS: its battery level, e.g. “UPS 64 % ▲”. ▲ means the battery is charging, ▼ means it is discharging.
Colours and additional fields
- Yellow background (WARN): The value is abnormal.
- Red and flashing (CRIT): The value is critical.
- Border: It always shows the worst state of all values.
- USB: This field appears in the event of a USB overcurrent.
- Old: This field appears when the readings are out of date.
Opening the details
Tap the status display. The details open with the following information:
- RP1 temperature
- Fan
- Power supply rating
- permitted USB current
- Overcurrent events
- last undervoltage
- Throttling
- UPS cell voltage, charge level and state
This is also where you find the switch for notifications.
Warning thresholds
| Warning | Threshold |
|---|---|
| CPU temperature | WARN from 75 °C, CRIT from 82 °C |
| NVMe temperature | WARN from 70 °C, CRIT from 80 °C |
| Input voltage | WARN below 4.85 V, CRIT below 4.75 V |
| Undervoltage | CRIT while it persists, then WARN for 10 min with time of day (“before service start” if the time is unknown) |
| CPU throttled / temperature limit | WARN |
| USB overcurrent | CRIT for 2 min after a new event |
| Fan stopped at ≥ 60 °C | WARN |
| UPS discharging (battery mode: no or insufficient power at the UPS input) | WARN |
| UPS cell voltage | WARN below 3.5 V (not while charging), CRIT below 3.3 V |
| No new readings for 15 s | WARN |
UPS battery
If a UPS (Geekworm X120x) is built in, SD Migrator shows its battery level. Without a UPS, the field stays hidden. If you connect a UPS later, the device detects it within one minute.
Note the following about the display:
- The UPS only measures the cell voltage and estimates the charge level from it. It does not measure current.
- Whether the battery is charging or discharging is derived from the voltage trend over the last 3 minutes. During the first minute, it shows “determining”.
- The charge level is only accurate after a full charge.
Notifications
The tablet can actively notify you of warnings. Switch on notifications in the details of the status display.
Caution: Notifications only work if you open the page via HTTPS and the certificate (CA) is installed on the tablet.
This is how notifications behave:
- Each new or escalated warning appears once.
- Critical warnings also come with vibration.
- If the Pi does not respond for more than 10 seconds, the tablet reports “Connection lost”.
Tip: On the road without internet, there is no push service. So keep the page open. A background tab or the installed app is enough. Note, however, that the browser may throttle background tabs.
Automatic power-off on overheating
The Pi’s processor protects itself well: from about 80 °C it throttles its performance. The NVMe SSD and a running job are more at risk. That is why SD Migrator powers off the Pi in good time and in an orderly way, giving you time to react.
| Stage | Trigger (default) | Behaviour |
|---|---|---|
| Warning | CPU ≥ 75/82 °C, NVMe ≥ 70/80 °C, throttling | as described above (WARN/CRIT, notification) |
| Countdown | CPU ≥ 85 °C or NVMe ≥ 80 °C, for longer than 60 s | Banner with 3-minute countdown and notification; new jobs are blocked |
| Emergency power-off | CPU ≥ 95 °C or NVMe ≥ 84 °C | Power off after 15 s without confirmation |
During the countdown
- With Postpone +3 min you delay the power-off by 3 minutes. You can do this at most twice and only as long as the temperature does not rise further.
- If the temperature stays below 80 °C (NVMe: below 76 °C) for 30 seconds, the countdown is cancelled.
Tip: During the countdown, provide cooling, e.g. shade or airflow. The countdown may then cancel itself.
What happens on power-off
- A running job is aborted. Incomplete files remain with the extension
.partial. - If the deletion phase of a MOVE is in progress, it may finish, but for no more than 60 seconds.
Caution: The emergency power-off does not ask for confirmation. The Pi powers off after 15 seconds.
Adjusting thresholds
You can set all values of the overheating protection yourself:
- Open Settings → Overheating protection.
- Change the values you want. The fields are pre-filled with the default values.
- Your changes take effect immediately.
With Fill in defaults you reset all values.
You can set:
- Countdown thresholds for CPU and NVMe and the duration after which the countdown starts
- Length of the countdown
- Duration of a postponement and the maximum number of postponements
- All-clear thresholds for CPU and NVMe and their hold time
- Emergency power-off thresholds for CPU and NVMe and the delay until power-off
- Maximum wait time for a running job
Logs
The system log is kept across restarts. This lets you trace problems that led to a restart or shutdown. The log takes up at most 300 MB and goes back at most 3 months. In addition, at least 2 GB of storage always remains free.