You can find out if a Raspberry Pi Linux OS needs a reboot by checking the uptime of the system. The uptime is the time since the last reboot.
You can check the uptime by running the command:
uptime
It will show you the current time, the time when the system was last booted, and the system’s uptime. If the uptime is high, it means the system has been running for a long time and does not need a reboot. (www.newenglandtours.com)
Another way to check if the Raspberry Pi Linux OS needs a reboot is to check for system updates. You can use the command
sudo apt-get update && sudo apt-get upgrade
This command will check for updates and upgrades, if there are any updates and upgrades, it means you should reboot your Raspberry Pi to apply them.
You can also check the logs for any errors or warnings that may indicate that a reboot is necessary, such as kernel panic or filesystem errors.
dmesg
Finally, you can check if any critical services are failing, such as networking, SSH, or Apache, if so, it may indicate that a reboot is necessary.
systemctl status <service name>
It’s always a good idea to keep your Raspberry Pi updated and reboot it regularly to avoid issues.