Kdump is the Linux kernel crash-dump mechanism. Oracle recommends that you enable the
Kdump feature. In the event of a system crash, Kdump creates a memory image
(vmcore
) that can help in determining the cause of the crash. Enabling
Kdump requires you to reserve a portion of system memory for exclusive use by Kdump. This
memory is unavailable for other uses.
Kdump uses kexec
to boot into a second kernel whenever the system
crashes. kexec
is a fast-boot mechanism which allows a Linux kernel to boot
from inside the context of a kernel that is already running without passing through the
bootloader stage.