Use a mix of external checks and on-server tools.
- External monitoring: a free service like UptimeRobot pings your site or IP every few minutes and emails or texts you if it goes down, this catches outages even when the whole server is unreachable.
- On the server: run
uptimeto see how long it's been running and the load average, orsystemctl statusto check that key services (web, database) are active. - Auto-restart services with systemd's
Restart=alwaysso crashes recover on their own.
The VPS control panel in your client area may also show status and basic graphs. If your server keeps going offline, open a ticket so Toshost can check the host node and network.