mjhjmtu

I do not understand the purpose of the mount_root_run_init action in kdump.conf:

# default <reboot | halt | poweroff | shell | mount_root_run_init>
# - Action to preform in case dumping to intended target
# fails. If no default action is specified, "reboot"
# is assumed default.
#
# reboot: If the default action is reboot simply reboot
# the system and loose the core that you are
# trying to retrieve.
# halt: If the default action is halt, then simply
# halt the system after attempting to capture
# a vmcore, regardless of success or failure.
# poweroff: The system will be powered down
# shell: If the default action is shell, then drop to
# an hush session inside the initramfs from
# where you can try to record the core manually.
# Exiting this shell reboots the system.
# mount_root_run_init: Mount root filesystem and run init. Kdump
# initscript will try to save dump to root
# filesystem in /var/crash dir. This will
# likely require a lot more memory to
# be reserved for kdump kernel.

What I undestood is that when current kernel is crashed, kdump boots into second kernel which was already reserved in memory and then it collects the kernel core dump to a specified target.

So, it does the default action if it fails to collect to a specified target.

Why does it mount root filesystem and run init?
To make the / filesystem available to the second kernel and to load required services/modules for the collecting process?

If it's the case, how was the following supposed to work (as / filesystem is not mounted in second kernel by that time)

action to preform in case dumping to intended target fails.

Say, I mentioned /var/custom-crash to be my target path, will it work?