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diff --git a/man/systemd-halt.service.xml b/man/systemd-halt.service.xml
index 6a6bfdc7d..552dbdf68 100644
--- a/man/systemd-halt.service.xml
+++ b/man/systemd-halt.service.xml
@@ -65,7 +65,7 @@
systemd-halt.service is a
system service that is pulled in by
halt.target and is responsible
- for the actual system halt. Similar,
+ for the actual system halt. Similarly,
systemd-poweroff.service is
pulled in by poweroff.target,
systemd-reboot.service by
@@ -74,25 +74,31 @@
kexec.target to execute the
respective actions.
- When these services are run they ensure that PID
+ 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
+ shutdown. Before shutting down, this binary will try to
unmount all remaining file systems, 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 â
+ 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.
+
Immediately before executing the actual system
halt/poweroff/reboot/kexec
systemd-shutdown will run all
executables in
/usr/lib/systemd/system-shutdown/
and pass one arguments to them: either
- "halt",
- "poweroff",
- "reboot" or
- "kexec", depending on the chosen
+ halt,
+ poweroff,
+ 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.
@@ -101,7 +107,7 @@
systemd-halt.service (and the
related units) should never be executed
directly. Instead, trigger system shutdown with a
- command such as "systemctl halt" or
+ command such as systemctl halt or
suchlike.