kexec

Boot from the currently running kernel to a new kernel

Supplementary instructions

kexec command is a patch to the Linux kernel that allows you to boot directly into a new kernel from the currently running kernel. In the boot sequence described above, kexec skips the entire boot loader stage (the first part) and jumps directly to the kernel we wish to boot into. No more hardware reboots, no more firmware operations, no more boot loaders involved. Completely avoiding the weakest link in the boot sequence - the firmware. The biggest benefit of this feature is that the system can now be restarted extremely quickly.

Benefits of kexec: Systems that require high availability, as well as kernel developers who need to constantly reboot their systems, will benefit from kexec. Because kexec skips the most time-consuming part of the system reboot process (that is, the stage where the firmware initializes the hardware devices), the reboot becomes very fast and availability is improved.

grammar

kexec(option)

Options

-l: Specify the kernel image file;
-e: Allow the currently loaded kernel;
-f: Forces the system call "kexec" to be called immediately without calling "shutdown";
-t: Specifies the type of new kernel;
-u: Uninstall the current kexec target kernel.