High-performance servers are crucial for mission-critical applications and services. However, these servers can occasionally encounter various errors. In this article, we will guide you step-by-step on how to diagnose and resolve one of the most common issues: kernel panic.
What is Kernel Panic?
Kernel panic occurs when the operating system's kernel encounters an unexpected error. In this case, the system stops functioning and typically requires a reboot.
Diagnosing Kernel Panic Error
Follow these steps to diagnose kernel panic:
1. Check System Logs
First, use the dmesg command to check the system logs:
sudo dmesg | less
This command shows events that occurred during system startup. Look for errors related to kernel panic.
2. Monitor CPU and Memory Usage
To check CPU and memory usage, you can use top or htop commands:
top
or
htop
These commands display the CPU and memory usage on the system. High usage scenarios can lead to kernel panic.
3. Inspect Kernel Error Messages
Take note of the error messages displayed on the screen during kernel panic. These messages can help you identify the root cause of the problem.
Fixing Kernel Panic Error
To fix kernel panic, follow these steps:
1. Boot the Server in Safe Mode
To boot the server in safe mode, press e in the GRUB menu during startup to make changes. Then, add single to the linux line:
linux /vmlinuz-... root=/dev/sda1 single
This allows the server to boot in single-user mode.
2. Enable Debugging Mode
To activate debugging mode, update sysctl settings with the following command:
sudo sysctl -w kernel.panic=0
This setting prevents the system from rebooting when kernel panic occurs.
3. Update Kernel
Kernel panic may be caused by an outdated or faulty kernel version. To update the kernel, use the following command:
To troubleshoot kernel-related issues, restart the relevant services with the following command:
sudo systemctl restart
Here, is the name of the service related to the error, such as mysql or apache2.
5. Hardware Check
Kernel panic can sometimes be caused by hardware issues. To check the RAM and disk status:
sudo memtest
and
sudo smartctl -a /dev/sda
commands can be used.
Conclusion
Kernel panic is a critical issue in high-performance servers. By following the steps outlined above, you can diagnose and fix this error. If the problem persists, consider checking your server hardware or seeking professional support.