From 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 22:49:52 +0200 Subject: Adding upstream version 255.4. Signed-off-by: Daniel Baumann --- man/systemd-poweroff.service.xml | 90 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 man/systemd-poweroff.service.xml (limited to 'man/systemd-poweroff.service.xml') diff --git a/man/systemd-poweroff.service.xml b/man/systemd-poweroff.service.xml new file mode 100644 index 0000000..b430170 --- /dev/null +++ b/man/systemd-poweroff.service.xml @@ -0,0 +1,90 @@ + + + + + + + + systemd-poweroff.service + systemd + + + + systemd-poweroff.service + 8 + + + + systemd-poweroff.service + systemd-halt.service + systemd-reboot.service + systemd-kexec.service + systemd-shutdown + System shutdown logic + + + + systemd-poweroff.service + systemd-halt.service + systemd-reboot.service + systemd-kexec.service + /usr/lib/systemd/systemd-shutdown + /usr/lib/systemd/system-shutdown/ + + + + Description + + systemd-poweroff.service is a system service that is pulled in by + poweroff.target and is responsible for the actual system power-off + operation. Similarly, systemd-halt.service is pulled in by + halt.target, systemd-reboot.service by + reboot.target and systemd-kexec.service by + kexec.target to execute the respective actions. + + When these services are run, they ensure that PID 1 is replaced by the + /usr/lib/systemd/systemd-shutdown tool which is then responsible for the actual + shutdown. Before shutting down, this binary will try to unmount all remaining file systems (or at least + remount them read-only), disable all remaining swap devices, detach all remaining storage devices and + kill all remaining processes. + + It is necessary to have this code in a separate binary because otherwise rebooting after an upgrade + might be broken — the running PID 1 could still depend on libraries which are not available any more, + thus keeping the file system busy, which then cannot be re-mounted read-only. + + Shortly before executing the actual system power-off/halt/reboot/kexec + systemd-shutdown will run all executables in + /usr/lib/systemd/system-shutdown/ and pass one arguments to them: either + poweroff, halt, reboot, or + kexec, depending on the chosen action. All executables in this directory are executed + in parallel, and execution of the action is not continued before all executables finished. Note that + these executables are run after all services have been shut down, and after most + mounts have been detached (the root file system as well as /run/ and various API + file systems are still around though). This means any programs dropped into this directory must be + prepared to run in such a limited execution environment and not rely on external services or hierarchies + such as /var/ to be around (or writable). + + Note that systemd-poweroff.service (and the related units) should never be + executed directly. Instead, trigger system shutdown with a command such as systemctl + poweroff. + + Another form of shutdown is provided by the + systemd-soft-reboot.service8 + functionality. It reboots only the OS userspace, leaving the kernel, firmware, and hardware as it is. + + + + See Also + + systemd1, + systemctl1, + systemd.special7, + reboot2, + systemd-suspend.service8, + systemd-soft-reboot.service8, + bootup7 + + + + -- cgit v1.2.3