vault backup: 2025-03-20 11:07:48

2 files changed, 29 insertions, 1 deletions

diff --git a/3 Resources/Systemd/Systemd restart signal.md b/3 Resources/Systemd/Systemd restart signal.md
new file mode 100644
index 0000000..3497069
--- /dev/null
+++ b/3 Resources/Systemd/Systemd restart signal.md
@@ -0,0 +1,25 @@
+---
+tags:
+  - systemd
+  - restart
+references:
+  - https://www.reddit.com/r/linuxquestions/comments/10eu3i0/does_systemctl_restart_send_sigterm_signal/?rdt=64556
+---
+By default, `restart` does exactly the same thing as `stop` followed by `start`.
+
+`stop` will:
+
+- execute `ExecStop=` commands, if any;
+    
+- send the signal defined by `KillSignal=` (default: `SIGTERM`), to any remaining processes identified by the `KillMode=`;
+    
+- send `SIGCONT` to those same processes;
+    
+- if `SendSIGHUP=` is true (default: false), send `SIGHUP` to those same processes;
+    
+- if `SendSIGKILL=` is true (default: true), and any processes remain after `TimeoutStopSec=`, send the `FinalKillSignal=` (default: `SIGKILL`) to those remaining processes;
+    
+- execute `ExecStopPost=` commands, if any.
+    
+
+`restart` changes this by using `RestartKillSignal=` instead of `KillSignal=`, but if `RestartKillSignal=` is not set it just inherits its value from `KillSignal=`. And, of course, `restart` then performs all the regular `start` actions after everything else. `restart` also differs from `stop` by not flushing the file descriptor store associated with the service.
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diff --git a/3 Resources/Systemd/Unit types.md b/3 Resources/Systemd/Unit types.md
index 27ee387..51bb40f 100644
--- a/3 Resources/Systemd/Unit types.md
+++ b/3 Resources/Systemd/Unit types.md
@@ -5,10 +5,13 @@ tags:
 ---
 The `Type` directive is specified within the `Service` section. There are 6 different types;
 - **Simple**: The default if `Type` nor `Busname` are specified.
+- **Exec** : similar to simple but waits a bit more for the service to be started successfully
 - **Forking**: Used when the parent process exits immediately due to it forking. Systemd will know it's still running even though it exited.
 - **Oneshot**: When the process is short-lived and doesn't need to keep running. Systemd will wait on the process before starting other units.
 - **Dbus**: The process will be registered on the D-Bus bus.
 - **Notify**: Systemd will expect a notification from the process to signal it has started up blocking the execution of other units until the signal is received.
 - **Idle**: Service will not run ufntil all jobs are dispatched. #clarify
 
-https://www.digitalocean.com/community/tutorials/understanding-systemd-units-and-unit-files#unit-specific-section-directives
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+https://www.digitalocean.com/community/tutorials/understanding-systemd-units-and-unit-files#unit-specific-section-directives
+
+**Exec** is recommended by `man systemd.service` for long-running services.
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