One of the most critical errors encountered in physical servers is kernel panic, where the server's operating system unexpectedly halts due to an issue. This error can arise from hardware failures, incompatible software, or misconfigurations. In this article, we will define kernel panic and explain how to resolve it step by step using SSH commands.
Causes of Kernel Panic
The main causes of kernel panic include:
Hardware failures (RAM, disk, motherboard)
Incompatible or corrupted software
Misconfigured kernel modules
Errors after updates
Step 1: Check Server Status
First, check the server's status by reviewing the system logs with the following command:
sudo journalctl -xe
This command will list recent errors and warnings on the system. Look for any error messages related to kernel panic.
Step 2: Hardware Check
To check for hardware failures, follow these steps:
Use the memtest86+ tool to test the RAM:
sudo apt-get install memtest86+
Then reboot the server and run memtest86+ to test the RAM.
Step 3: Check Software and Updates
Kernel panic can sometimes occur after software updates. Check for updates with the following command:
sudo apt-get update && sudo apt-get upgrade
After completing the updates, restart the server.
Step 4: Check Kernel Modules
Misconfigured kernel modules can also cause kernel panic. Check the following file:
/etc/default/grub
To edit the file:
sudo nano /etc/default/grub
Make necessary changes and update grub:
sudo update-grub
Step 5: Boot Server in Safe Mode
If the above steps do not resolve the issue, try booting the server in safe mode. This allows the server to start with a minimal operating system. Follow these steps:
Reboot the server.
Press F8 at the BIOS screen to select the safe mode option.
Conclusion
Kernel panic can lead to serious issues in physical servers. By following the steps outlined above, you can diagnose the cause of this error and apply solutions to restore your server to a healthy operational state.