Boards recover on their own when memory runs out or the system hangs

On a board short of memory, the screen could freeze, or the whole board could stop responding until someone power cycled it. Anthias 2026.09.0 changes how both cases end.

Running out of memory

When memory runs out, the viewer container is meant to be what the system stops, because Docker then restarts it clean. Before, only the small script that starts the viewer was marked to go first, and stopping it freed almost nothing. In the project's testing on a 2 GB board with an RK3566 chip, the system stopped that script twice in a row, got back less than 200 KB each time, and still had to stop something else. Every process in the viewer container is now marked, so the first thing stopped is the viewer itself, and in the same test that freed about 100 MB at once.

A board that stops responding

When you install or upgrade with the installer, it now sets up systemd's watchdog with a 30 second timeout, so a board whose system hangs reboots by itself. Which watchdog it uses depends on the board:

• Raspberry Pi boards use the Pi's hardware watchdog. Raspberry Pi OS already had it switched on with a 1 minute timeout, and Armbian and Debian ship it off.
• On x86, any hardware watchdog the machine exposes is used, and the kernel's software watchdog otherwise.
• Other boards, such as the Rock Pi 4 and the NanoPi R3S, use the software watchdog. In the project's testing, the hardware watchdog on both of those boards halted the board instead of restarting it, and it stayed dark until someone power cycled it. The software watchdog restarted the Rock Pi 4 within about 30 seconds.

A board with no watchdog that can restart it gets the watchdog switched off explicitly, rather than left to the system default. A reboot that hangs while shutting down is forced through after 5 minutes.