https://www.techtarget.com/searchdatacenter/definition/kernel-panic
A kernel panic refers to a computer error from which the system's operating system (OS) cannot quickly or easily recover. It occurs when there is a low-level fatal error and the operating system's kernel is unable to fix it.
A kernel panic error stops the system to prevent corruption of the system's software, hardware or memory. It helps preserve data and allows technicians to run a debugger to determine the problem.
The term applies primarily to Unix-based operating systems such as Linux and BSD, and also to Mac OS X. The kernel panic error is similar to the blue screen of death (BSOD) error in Windows-based systems.
A kernel panic results in a failure to boot. It is used by an OS kernel to alert users to a problem, and prevent further issues once detected. During a kernel panic, the OS writes the contents of the kernel memory -- also known as a kernel dump -- to the disk. It also stops all CPU operations. To restart operations, the OS reboots automatically or waits for the user to reboot manually. The action taken depends on the OS configuration.
A kernel panic produces a message or set of messages on the computer display This message may include information about error type, code module running at the time of the error and loaded drives.
It also creates a log detailing what happened. This information means little to inexperienced end users, but it can help technicians and troubleshooting teams diagnose and resolve system problems.
A kernel panic is not the same as a system crash, although both can be annoying and even cause serious issues for the end user. In a kernel panic, the kernel terminates abnormally. In a system crash, the kernel forcefully terminates a software execution after detecting an abnormal condition. The goal is to minimize data loss or corruption in the device.
Kernel panic can be triggered by an inappropriate attempt by the OS to access or write to memory, and can also be caused by software bugs or malware. Other common causes of a kernel panic include:
In Linux systems, kernel panic may be due to:
A Linux kernel panic is a system boot issue that occurs when the kernel can't load properly, and prevents the system from booting. It usually manifests as a black screen filled with code.
During a normal boot process, the kernel (vmlinuz) doesn't load directly. Instead, the initramfs file loads in the RAM. The file then points to the kernel which then results in OS booting. However, if the initramfs file is corrupted or deleted, it results in kernel panic. Such corruptions can occur due to recent OS updates or patches.
On Linux systems, "kernel oops" refers to a serious error that the OS can't handle. Even if the system continues to run, it may cause instability issues, and result in a full kernel panic. Not all kernel oops errors cause a kernel panic, although many do.
Kernel panic in a Mac is due to a failure of the macOS kernel. It usually results in sudden system restarts or a display message that instructs the user to manually restart. If kernel panics happen frequently, they can disrupt user workflows, result in data loss, and even affect the health of the Mac system.
The most common reasons for kernel panic in a macOS are:
There are many reasons and causes for kernel panic errors. Here are several ways to troubleshoot and resolve the problem:
Out-of-date or corrupt software versions can cause problems for Mac systems, including kernel panic. To avoid the error, update all software and drivers. The process is straightforward:
Mac crash reports can provide useful insights about kernel panic issues. To access these reports, navigate to Applications > Utilities and access the log viewer named Console. Crash reports are displayed in the console. They contain information about kernel panics, including causes. This information helps technicians start the troubleshooting process.
Kernel extensions that facilitate communication between hardware and the Mac can also cause kernel panic. To remove suspicious external kexts, users should:
Freeing up disk space can help ensure the smooth processing of multiple apps and operations. Users can free up space by manually inspecting files and software and removing the assets that are not being used. Removing unused processes can also free up space in the memory and minimize the possibility of kernel panics.
Kernel panic is essentially an indication of the system's inability to execute some functions. This implies a lack of enough RAM or the presence of a malfunctioning RAM. Replacing the malfunctioned RAM can restore proper functioning and mitigate the risk of kernel panic.
In Windows, kernel panic is typically characterized by the appearance of a BSOD error message stating that the system needs a restart. The error is usually caused by malfunctioning hardware or poorly optimized device drivers.
The steps to troubleshoot kernel panics in Windows are similar to the steps undertaken to troubleshoot kernel panics in Mac systems.
Although kernel panics are less probable in newer Android OS versions due to Android security updates and kernel optimizations, they can occur. Similar to other OSes, kernel panics in Android are usually hardware- or software-related. Other probable causes include faulty RAM, malfunctioning peripherals, plugins or programs. Updating to the latest Android version can help minimize the occurrence of kernel panics.
See also: Troubleshoot Linux kernel panic with the kdump crash tool, basic Linux commands for new Linux server administrators and how to troubleshoot when Windows 10 won't update.
05 Apr 2022