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In computing, kexec (kernel execution) is a mechanism of the Linux kernel that allows "live" booting of a new kernel "over" the currently running kernel. kexec skips the bootloader stage (hardware initialization phase by the firmware or BIOS) and directly loads the new kernel into memory, where it starts executing immediately. This avoids the long times associated with a full reboot[1], and can help systems to meet high-availability requirements by minimizing downtime.