finalrd

FINALRD(1)                          finalrd                         FINALRD(1)

NAME
       finalrd - final runtime directory generator for shutdown

SYNOPSIS
        systemctl enable --now finalrd.service

HOOKS DIRECTORIES
        /usr/share/finalrd/*.finalrd
        /etc/finalrd/*.finalrd
        /run/finalrd/*.finalrd

HOOKS INTERFACE
        foo.finalrd setup
        foo.finalrd halt|poweroff|reboot|kexec

DESCRIPTION
       finalrd generates a shutdown directory /run/initramfs which systemd-
       shutdown pivots to during shutdown. There system shutdown can be
       finalised and arbitrary hooks can be executed off-root, to safely
       cleanup rootfs and perform any other shutdown tasks.

       For example, a hook may takeover monitoring external metadata RAID
       arrays, wait for them to be clean, and stop them. If one is using
       iscsiroot, it maybe needed to perform iscsi logout on shutdown.

       Typically, one would not run finalrd directly, but instead activate
       finalrd.service. This would execute finalrd generator late in the
       shutdown cycle, just in time for pivot.

HOOKLESS OPERATION
       If initramfs-tools is not available, and thus copy_exec is not
       available, hooks will not be executed or copied into the shutdown
       directory. However, shutdown dir will still be created to ensure init
       has somewhere to pivot, and attempt a cleaner shutdown without holding
       up the root filesystem.

       For example, Ubuntu Core is such system.

HOOKS INTERFACE DESCRIPTION
       *.finalrd hooks can be shipped in /usr, /etc, /run. These directories
       are for distribution, sysadmin, and transient hooks respectively.

       They are multi-purpose binaries with action passed as the first
       argument.

       During setup stage, hooks are executed from the rootfs with one
       argument setup passed as the first arg. All hooks are executed in all
       the directories in order, first everything in /usr, then from /etc,
       then from /run. Environmental variables DESTDIR and DESTROOTDIR are set
       pointing at the finalrd location. This is done for convenience to use
       initramfs-tools's copy_exec function or dracut-install, for copying
       binaries.

       During shutdown stage, hooks are executed from finalrd in parallel with
       one argument passed to them. The argument is one of halt, poweroff,
       reboot, kexec.

       Note if there are identically named hooks in multiple configuration
       directories, all of them will be executed during setup stage. But only
       the last one will be copied into the finalrd and executed during the
       shutdown stage.

SEE ALSO
       The initrd Interface of systemd
       <https://www.freedesktop.org/wiki/Software/systemd/InitrdInterface>

finalrd 2                                                           FINALRD(1)