Systemd: Difference between revisions
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=Locations= | | ||
= Documentation = | |||
*[https://www.dynacont.net/documentation/linux/Useful_SystemD_commands/ Useful systemd commands] | |||
*[http://www.freedesktop.org/wiki/Software/systemd/ http://www.freedesktop.org/wiki/Software/systemd/] | |||
*[https://wiki.ubuntu.com/systemd https://wiki.ubuntu.com/systemd] | |||
*[https://wiki.archlinux.org/index.php/Systemd Creating systemd service] | |||
*[https://wiki.ubuntu.com/SystemdForUpstartUsers https://wiki.ubuntu.com/SystemdForUpstartUsers] | |||
*[https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units How To Use Systemctl to Manage Systemd Services and Units] | |||
*[http://xmodulo.com/switch-from-networkmanager-to-systemd-networkd.html How to switch from NetworkManager to systemd-networkd on Linux] | |||
*[https://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet https://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet] | |||
*[https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/ Predictable Network Interface Names] | |||
*[[https://blog.darknedgy.net/technology/2020/05/02/0/index.html#tech-critique https://blog.darknedgy.net/technology/2020/05/02/0/index.html#tech-critique] | |||
*[https://mohsensy.github.io/sysadmin/2018/08/19/systemd-service-tutorial.html Systemd service tutorial] | |||
*[https://www.freedesktop.org/wiki/Software/systemd/dbus/ https://www.freedesktop.org/wiki/Software/systemd/dbus/ Systemd and dbus] | |||
*[https://www.thegeekdiary.com/how-to-boot-into-rescue-mode-or-emergency-mode-through-systemd-in-centos-rhel-7-and-8/ Single user/emergency] | |||
= Locations = | |||
/etc/systemd | /etc/systemd | ||
/usr/lib/systemd/ | /usr/lib/systemd/ | ||
/lib/systemd | |||
| |||
= HOWTO = | |||
== Timers == | |||
*[https://opensource.com/article/20/7/systemd-timers https://opensource.com/article/20/7/systemd-timers] | |||
*[https://wiki.archlinux.org/title/Systemd/Timers https://wiki.archlinux.org/title/Systemd/Timers] | |||
man systemd.timer | |||
=== List active timers === | |||
systemctl list-timers | |||
=== List all timers === | |||
systemctl list-timers --all | |||
=== Create timer === | |||
systemctl enable fstrim.timer | |||
== Auto restart crashed services == | |||
systemctl edit elasticsearch.service | |||
add: | |||
[Service] | |||
Restart=always | |||
then | |||
systemctl daemon-reload | |||
systemctl restart elasticsearch.service | |||
And to get an email when service gets restarted: https://dev.to/setevoy/linux-systemd-unit-files-edit-restart-on-failure-and-email-notifications-5h3k | |||
= FAQ = | |||
== Fix journal size == | |||
journalctl --vacuum-time=10d | |||
or | |||
journalctl --vacuum-size=1G | |||
===Journal settings=== | |||
/etc/systemd/journald.conf | |||
SystemMaxUse=1G | |||
and then | |||
systemctl restart systemd-journald.service | |||
== Analyze boot processes == | |||
systemd-analyze blame | |||
= | | ||
==syslog spam== | |||
https://psyq123.wordpress.com/2015/06/29/if-you-get-a-lot-of-logspam-from-systemd-in-your-varlogsyslog-this-might-help/ | | ||
| |||
== Systemd and DNS == | |||
resolvectl status | |||
=== Failed to get global data: Unit dbus-org.freedesktop.resolve1.service not found. === | |||
Means systemd-resolved is not running | |||
Restart: | |||
systemctl restart systemd-resolved | |||
| |||
=== Add nameserver === | |||
Sacrifice a chicken | |||
| |||
=== Flush caches === | |||
systemd-resolve --flush-caches | |||
== All status == | |||
systemctl status -a | |||
== syslog spam == | |||
[https://psyq123.wordpress.com/2015/06/29/if-you-get-a-lot-of-logspam-from-systemd-in-your-varlogsyslog-this-might-help/ https://psyq123.wordpress.com/2015/06/29/if-you-get-a-lot-of-logspam-from-systemd-in-your-varlogsyslog-this-might-help/] | |||
== list available services == | |||
systemctl list-unit-files | systemctl list-unit-files | ||
or | or | ||
systemctl list-units | systemctl list-units | ||
| |||
== normal interface names == | |||
net.ifnames=0 | |||
== Show failed services == | |||
systemctl --failed | |||
| |||
== systemd: Started Session == | |||
Change loglevel to notice in /etc/systemd/system.conf | |||
systemctl daemon-reexec | |||
==Status== | |||
=== Active: inactive (dead) === | |||
parameter ActiveState would return inactive | |||
SubState returns dead | |||
Revision as of 20:36, 20 May 2022
Documentation
- Useful systemd commands
- http://www.freedesktop.org/wiki/Software/systemd/
- https://wiki.ubuntu.com/systemd
- Creating systemd service
- https://wiki.ubuntu.com/SystemdForUpstartUsers
- How To Use Systemctl to Manage Systemd Services and Units
- How to switch from NetworkManager to systemd-networkd on Linux
- https://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet
- Predictable Network Interface Names
- [https://blog.darknedgy.net/technology/2020/05/02/0/index.html#tech-critique
- Systemd service tutorial
- https://www.freedesktop.org/wiki/Software/systemd/dbus/ Systemd and dbus
- Single user/emergency
Locations
/etc/systemd /usr/lib/systemd/ /lib/systemd
HOWTO
Timers
man systemd.timer
List active timers
systemctl list-timers
List all timers
systemctl list-timers --all
Create timer
systemctl enable fstrim.timer
Auto restart crashed services
systemctl edit elasticsearch.service
add:
[Service] Restart=always
then
systemctl daemon-reload systemctl restart elasticsearch.service
And to get an email when service gets restarted: https://dev.to/setevoy/linux-systemd-unit-files-edit-restart-on-failure-and-email-notifications-5h3k
FAQ
Fix journal size
journalctl --vacuum-time=10d
or
journalctl --vacuum-size=1G
Journal settings
/etc/systemd/journald.conf
SystemMaxUse=1G
and then
systemctl restart systemd-journald.service
Analyze boot processes
systemd-analyze blame
Systemd and DNS
resolvectl status
Failed to get global data: Unit dbus-org.freedesktop.resolve1.service not found.
Means systemd-resolved is not running
Restart:
systemctl restart systemd-resolved
Add nameserver
Sacrifice a chicken
Flush caches
systemd-resolve --flush-caches
All status
systemctl status -a
syslog spam
list available services
systemctl list-unit-files
or
systemctl list-units
normal interface names
net.ifnames=0
Show failed services
systemctl --failed
systemd: Started Session
Change loglevel to notice in /etc/systemd/system.conf
systemctl daemon-reexec
Status
Active: inactive (dead)
parameter ActiveState would return inactive
SubState returns dead
