> ## Documentation Index
> Fetch the complete documentation index at: https://docs.siderolabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Watchdog Timers

> Using hardware watchdogs to workaround hardware/software lockups.

export const VersionWarningBanner = () => {
  const latestVersion = "v1.13";
  const [latestUrl, setLatestUrl] = useState(null);
  const [currentVersion, setCurrentVersion] = useState(null);
  const [isBeta, setIsBeta] = useState(false);
  const parseVersion = v => v.replace("v", "").split(".").map(Number);
  const isGreaterVersion = (a, b) => {
    const [aMajor, aMinor] = parseVersion(a);
    const [bMajor, bMinor] = parseVersion(b);
    if (aMajor > bMajor) return true;
    if (aMajor === bMajor && aMinor > bMinor) return true;
    return false;
  };
  useEffect(() => {
    if (typeof window === "undefined") return;
    const {pathname, hash, search} = window.location;
    const match = pathname.match(/\/talos\/(v\d+\.\d+)\//);
    if (!match) return;
    const detectedVersion = match[1];
    if (detectedVersion === latestVersion) return;
    setCurrentVersion(detectedVersion);
    if (isGreaterVersion(detectedVersion, latestVersion)) {
      setIsBeta(true);
    }
    const newPath = pathname.replace(`/talos/${detectedVersion}/`, `/talos/${latestVersion}/`);
    setLatestUrl(`${newPath}${search}${hash}`);
  }, []);
  if (!latestUrl || !currentVersion) return null;
  return <div className="not-prose sticky top-6 z-50 my-6">
      <div className="border border-yellow-500/30 bg-yellow-500/10 px-4 py-3 rounded-xl">
        <div className="text-sm">
          {isBeta ? <>
              ⚠️ You are viewing a <strong>beta version</strong> of Talos ({currentVersion}).
              This version may be unstable.
              <a href={latestUrl} className="ml-2 underline text-yellow-400 hover:text-yellow-300 font-medium">
                View latest stable version {latestVersion} →
              </a>
            </> : <>
              ⚠️ You are viewing an older version of Talos ({currentVersion}).
              <a href={latestUrl} className="ml-2 underline text-yellow-400 hover:text-yellow-300 font-medium">
                View the latest version {latestVersion} →
              </a>
            </>}
        </div>
      </div>
    </div>;
};

<VersionWarningBanner />

Talos Linux now supports hardware watchdog timers configuration.
Hardware watchdog timers allow to reset (reboot) the system if the software stack becomes unresponsive.
Please consult your hardware/VM documentation for the availability of the hardware watchdog timers.

## Configuration

To discover the available watchdog devices, run:

```shell theme={null}
$ talosctl ls /sys/class/watchdog/
NODE         NAME
172.20.0.2   .
172.20.0.2   watchdog0
172.20.0.2   watchdog1
```

The implementation of the watchdog device can be queried with:

```shell theme={null}
$ talosctl read /sys/class/watchdog/watchdog0/identity
i6300ESB timer
```

To enable the watchdog timer, patch the machine configuration with the following:

```yaml theme={null}
# watchdog.yaml
apiVersion: v1alpha1
kind: WatchdogTimerConfig
device: /dev/watchdog0
timeout: 5m
```

```shell theme={null}
talosctl patch mc -p @watchdog.yaml
```

Talos Linux will set up the watchdog time with a 5-minute timeout, and it will keep resetting the timer to prevent the system from rebooting.
If the software becomes unresponsive, the watchdog timer will expire, and the system will be reset by the watchdog hardware.

## Inspection

To inspect the watchdog timer configuration, run:

```shell theme={null}
$ talosctl get watchdogtimerconfig
NODE         NAMESPACE   TYPE                  ID      VERSION   DEVICE           TIMEOUT
172.20.0.2   runtime     WatchdogTimerConfig   timer   1         /dev/watchdog0   5m0s
```

To inspect the watchdog timer status, run:

```shell theme={null}
$ talosctl get watchdogtimerstatus
NODE         NAMESPACE   TYPE                  ID      VERSION   DEVICE           TIMEOUT
172.20.0.2   runtime     WatchdogTimerStatus   timer   1         /dev/watchdog0   5m0s
```

Current status of the watchdog timer can also be inspected via Linux sysfs:

```shell theme={null}
$ talosctl read /sys/class/watchdog/watchdog0/state
active
```