Path | Description
----------------------------------------------|------------------------------------
/etc/icinga2 | Contains Icinga 2 configuration files.
- /usr/lib/systemd/system/icinga2.service | The Icinga 2 Systemd service file on systems using Systemd.
- /etc/systemd/system/icinga2.service.d/limits.conf | On distributions with Systemd >227, additional service limits are required.
+ /usr/lib/systemd/system/icinga2.service | The Icinga 2 systemd service file on systems using systemd.
+ /etc/systemd/system/icinga2.service.d/limits.conf | On distributions with systemd >227, additional service limits are required.
/etc/init.d/icinga2 | The Icinga 2 init script on systems using SysVinit or OpenRC.
/usr/sbin/icinga2 | Shell wrapper for the Icinga 2 binary.
/usr/lib\*/icinga2 | Libraries and the Icinga 2 binary (use `find /usr -type f -name icinga2` to locate the binary path).
### Systemd Service <a id="systemd-service"></a>
-Some distributions (e.g. Fedora, openSUSE and RHEL/CentOS 7) use Systemd. The
-Icinga 2 packages automatically install the necessary Systemd unit files.
+Some distributions (e.g. Fedora, openSUSE and RHEL/CentOS 7) use systemd. The
+Icinga 2 packages automatically install the necessary systemd unit files.
-The Icinga 2 Systemd service can be (re-)started, reloaded, stopped and also
+The Icinga 2 systemd service can be (re-)started, reloaded, stopped and also
queried for its current status.
```
> **Tip**
>
-> If you are running into fork errors with Systemd enabled distributions,
+> If you are running into fork errors with systemd enabled distributions,
> please check the [troubleshooting chapter](15-troubleshooting.md#check-fork-errors).
### Init Script <a id="init-script"></a>
### Check Fork Errors <a id="check-fork-errors"></a>
-Newer versions of Systemd on Linux limit spawned processes for
+Newer versions of systemd on Linux limit spawned processes for
services.
* v227 introduces the `TasksMax` setting to units which allows to specify the spawned process limit.
* v231 changes the default value to 15%
This can cause problems with Icinga 2 in large environments with many
-commands executed in parallel starting with Systemd v228. Some distributions
+commands executed in parallel starting with systemd v228. Some distributions
also may have changed the defaults.
The error message could look like this:
External Resources:
* [Fork limit for cgroups](https://lwn.net/Articles/663873/)
-* [Systemd changelog](https://github.com/systemd/systemd/blob/master/NEWS)
+* [systemd changelog](https://github.com/systemd/systemd/blob/master/NEWS)
* [Icinga 2 upstream issue](https://github.com/Icinga/icinga2/issues/5611)
-* [Systemd upstream discussion](https://github.com/systemd/systemd/issues/3211)
+* [systemd upstream discussion](https://github.com/systemd/systemd/issues/3211)
### Systemd Watchdog <a id="check-systemd-watchdog"></a>
Usually Icinga 2 is a mission critical part of infrastructure and should be
online at all times. In case of a recoverable crash (e.g. OOM) you may want to
-restart Icinga 2 automatically. With Systemd it is as easy as overriding some
-settings of the Icinga 2 Systemd service by creating
+restart Icinga 2 automatically. With systemd it is as easy as overriding some
+settings of the Icinga 2 systemd service by creating
`/etc/systemd/system/icinga2.service.d/override.conf` with the following
content:
WatchdogSec=30s
-This way Systemd will kill Icinga 2 if does not notify for over 30 seconds, a timout of less than 10 seconds is not
+This way systemd will kill Icinga 2 if does not notify for over 30 seconds, a timout of less than 10 seconds is not
recommended. When the watchdog is activated, `Restart=` can be set to `watchdog` to restart Icinga 2 in the case of a
watchdog timeout.
Run `systemctl daemon-reload && systemctl restart icinga2` to apply the changes.
-Now Systemd will always try to restart Icinga 2 (except if you run
+Now systemd will always try to restart Icinga 2 (except if you run
`systemctl stop icinga2`). After three failures in ten seconds it will stop
trying because you probably have a problem that requires manual intervention.
> your changes.
There is a bug with existing sysconfig files where path variables are not expanded
-because Systemd [does not support](https://github.com/systemd/systemd/issues/2123)
+because systemd [does not support](https://github.com/systemd/systemd/issues/2123)
shell variable expansion. This worked with SysVInit though.
Edit the sysconfig file and either remove everything, or edit this line
ICINGA2_RLIMIT_FILES=50000
```
-Restart Icinga 2 afterwards, the Systemd service file automatically puts the
+Restart Icinga 2 afterwards, the systemd service file automatically puts the
value into the application's environment where this is read on startup.
### Setup Wizard Changes <a id="upgrading-to-2-9-setup-wizard-changes"></a>
- Alpine: boost-dev
* GNU bison (bison)
* GNU flex (flex) >= 2.5.35
-* Systemd headers
- - Only required when using Systemd
+* systemd headers
+ - Only required when using systemd
- Debian/Ubuntu: libsystemd-dev
- RHEL/Fedora: systemd-devel
#### Systemd <a id="development-package-builds-systemd"></a>
-If your distribution uses Systemd:
+If your distribution uses systemd:
```
systemctl {start|stop|reload|status|enable|disable} icinga2
```
-In case the distribution is running Systemd >227, you'll also
+In case the distribution is running systemd >227, you'll also
need to package and install the `etc/initsystem/icinga2.service.limits.conf`
file into `/etc/systemd/system/icinga2.service.d`.