kdump.service will not start

Issue

• The /var file system is mounted on a separate disk or logical volume than the / file system.
• When starting kdump service, we see the following messages.

kdumpctl[8848]: No kdump initial ramdisk found.
kdumpctl[8848]: Rebuilding /boot/initramfs-3.10.0-123.4.4.el7.x86_64kdump.img
kdumpctl[8848]: No dump target specified. Default dump target is rootfs block device.
kdumpctl[8848]: But dump path /var/crash is not backed by rootfs block device.
kdumpctl[8848]: Either explicitly specify a dump target or specify a dump path backed by rootfs block device
kdumpctl[8848]: mkdumprd: failed to make kdump initrd
kdumpctl[8848]: Starting kdump: [FAILED]
systemd[1]: kdump.service: main process exited, code=exited, status=1/FAILURE
systemd[1]: Failed to start Crash recovery kernel arming.
systemd[1]: Unit kdump.service entered failed state.