How to configure KDUMP on Oracle Linux 7

1). Install the kexec-tools package if not already installed:

To use the kdump service, you must have the kexec-tools package installed. To do so, type the following at a shell prompt as root:

# yum install kexec-tools

2). Configure kdump:

[1] Configure Memory usage

To configure the amount of memory that is reserved for the kdump kernel, edit  /etc/default/grub and modify GRUB_CMDLINE_LINUX , set the crashkernel=<size> parameter to the list of kernel options.

For example:

# cat /etc/default/grub

GRUB_TIMEOUT=5

GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"

GRUB_DEFAULT=saved

GRUB_DISABLE_SUBMENU=true

GRUB_TERMINAL_OUTPUT="console"