dracut-shutdown.service(category22-scripting.html) - phpMan

DRACUT-SHUTDOWN.S(8)                dracut                DRACUT-SHUTDOWN.S(8)
NAME
       dracut-shutdown.service - unpack the initramfs to /run/initramfs
SYNOPSIS
       dracut-shutdown.service
DESCRIPTION
       This service unpacks the initramfs image to /run/initramfs. systemd
       pivots into /run/initramfs at shutdown, so the root filesystem can be
       safely unmounted.
       The following steps are executed during a shutdown:
       o   systemd switches to the shutdown.target
       o   systemd starts
           /lib/systemd/system/shutdown.target.wants/dracut-shutdown.service
       o   dracut-shutdown.service executes
           /usr/lib/dracut/dracut-initramfs-restore which unpacks the
           initramfs to /run/initramfs
       o   systemd finishes shutdown.target
       o   systemd kills all processes
       o   systemd tries to unmount everything and mounts the remaining
           read-only
       o   systemd checks, if there is a /run/initramfs/shutdown executable
       o   if yes, it does a pivot_root to /run/initramfs and executes
           ./shutdown. The old root is then mounted on /oldroot.
           /usr/lib/dracut/modules.d/99shutdown/shutdown.sh is the shutdown
           executable.
       o   shutdown will try to umount every /oldroot mount and calls the
           various shutdown hooks from the dracut modules
       This ensures, that all devices are disassembled and unmounted cleanly.
       To debug the shutdown process, you can get a shell in the shutdown
       procedure by injecting "rd.break=pre-shutdown rd.shell" or
       "rd.break=shutdown rd.shell".
           # mkdir -p /run/initramfs/etc/cmdline.d
           # echo "rd.break=pre-shutdown rd.shell" > /run/initramfs/etc/cmdline.d/debug.conf
           # touch /run/initramfs/.need_shutdown
       In case the unpack of the initramfs fails,
       dracut-shutdown-onfailure.service executes to make sure switch root
       doesn't happen, since it would result in switching to an incomplete
       initramfs.
AUTHORS
       Harald Hoyer
SEE ALSO
       dracut(8)
dracut                            04/06/2024              DRACUT-SHUTDOWN.S(8)