What is kexec used for?
Kexec is a tool to boot to another kernel from the currently running one. You can perform faster system reboots without any hardware initialization. You can also prepare the system to boot to another kernel if the system crashes.
What is capture kernel?
Kdump is a standard Linux mechanism to dump machine memory content on kernel crash. Kdump is based on Kexec. Once dump capture kernel is booted, the user can use the file /proc/vmcore to get access to memory of crashed system kernel.
What is kexec in Linux?
kexec, abbreviated from kernel execute and analogous to the Unix/Linux kernel call exec, is a mechanism of the Linux kernel that allows booting of a new kernel from the currently running one. Memory of the currently running kernel is overwritten by the new kernel, while the old one is still executing.
What are Kexec tools?
Kexec is a system call that enables you to load and boot into another kernel from the currently running kernel. This is useful for kernel developers or other people who need to reboot very quickly without waiting for the whole BIOS boot process to finish.
How do I disable kexec?
This behaviour can be modified by setting the flag LOAD_EXEC in the file /etc/default/kexec to false. Note: After changing the flag, shutdown and boot the system for the change to take effect.
What does kexec do in the Linux kernel?
kexec is a system call that enables you to load and boot into another kernel from the currently running kernel. kexec performs the function of the boot loader from within the kernel.
Which is the call to the capture kernel?
One is the kernel space system call kexec_load, which is responsible for loading the capture kernel (capture kernel or send kernel) to the specified address when the production kernel (production kernel or first kernel) is started.
What is the optional initrd image for kexec?
The optional initrd-image is the initrd image to be used during boot. It’s also possible to invoke kexec without an option parameter. In that case, kexec loads the specified kernel and then invokes shutdown(1).
How is kdump used to analyze kernel crash?
The other is the user space tool kexec tools, which passes the address of the capture kernel to the production kernel, so that when the system crashes, it can find the address of the capture kernel and run it. No kdump without kexec. First, kexec realizes that you can start another kernel in one kernel, which makes kdump useful.