watchdog

System health monitoring and reset daemon

TLDR

Start watchdog daemon

$ sudo systemctl start watchdog

Enable at boot

$ sudo systemctl enable watchdog

Test configuration

$ sudo watchdog -v

Run in foreground

$ sudo watchdog -f

Force test mode

$ sudo watchdog -F

watchdog is a daemon that monitors system health and resets the system if problems are detected. It periodically writes to /dev/watchdog to prevent the kernel from triggering a hardware reset.The daemon can monitor various system conditions: load average, memory usage, file presence, process existence, temperature, and custom test scripts. If any check fails, the system reboots after logging the failure reason.Hardware watchdog support requires appropriate kernel modules (e.g., iTCO_wdt for Intel). Software watchdog via the softdog module provides fallback when hardware isn't available.

PARAMETERS

-f, --foreground

Run in foreground, don't fork.

-F, --force

Force test mode.

-v, --verbose

Verbose output.

-c file

Use specified configuration file.

-s, --sync

Sync before reboot.

--help

Display help.

CONFIGURATION

Config file: /etc/watchdog.confKey settings: watchdog-device, interval, max-load-1, min-memory, and test commands.

INSTALL

sudo apt install watchdog

sudo dnf install watchdog

sudo zypper install watchdog

nix profile install nixpkgs#watchdog

CAVEATS

Requires appropriate kernel watchdog driver. Improper configuration can cause unexpected reboots. Test thoroughly before production use. Software watchdog less reliable than hardware.

HISTORY

watchdog was developed for Linux systems requiring high availability without human intervention. The concept dates to embedded systems where hardware watchdog timers ensure recovery from system hangs. The Linux implementation combines hardware timer support with software monitoring.