linux:linux_systemd
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linux:linux_systemd [2021/11/05 16:03] manu |
linux:linux_systemd [2024/06/26 15:49] (current) manu |
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| - | ===== Manage services with systemd ===== | + | ====== Manage services with systemd ====== |
| Systemd is now used on most Linux distribution: Redhat, Suse, Ubuntu... | Systemd is now used on most Linux distribution: Redhat, Suse, Ubuntu... | ||
| Line 23: | Line 23: | ||
| ## List all services | ## List all services | ||
| <cli prompt='$'> | <cli prompt='$'> | ||
| - | $ systemctl list-units --type=service | + | $ systemctl list-units --type=service |
| + | $ systemctl list-units --type mount | ||
| </cli> | </cli> | ||
| Line 100: | Line 101: | ||
| ● ├─irqbalance.service | ● ├─irqbalance.service | ||
| </cli> | </cli> | ||
| + | |||
| ==== To enable NetworkManager, use: ==== | ==== To enable NetworkManager, use: ==== | ||
| === First, stop the running service: === | === First, stop the running service: === | ||
| - | systemctl is-active network.service && \ | + | <cli prompt='$'> |
| - | systemctl stop network.service | + | $ systemctl is-active network.service && systemctl stop network.service |
| + | </cli> | ||
| === Enable the NetworkManager service: === | === Enable the NetworkManager service: === | ||
| Line 118: | Line 121: | ||
| Check whether a service is already enabled or not: | Check whether a service is already enabled or not: | ||
| - | # systemctl is-enabled foo.service; echo $? | + | <cli prompt='$'> |
| + | $ systemctl is-enabled foo.service; echo $? | ||
| + | </cli> | ||
| 0 indicates that it is enabled. 1 indicates that it is disabled | 0 indicates that it is enabled. 1 indicates that it is disabled | ||
| === Start the NetworkManager service (via alias link): === | === Start the NetworkManager service (via alias link): === | ||
| - | systemctl start network.service | + | <cli prompt='$'> |
| + | $ systemctl start network.service | ||
| + | </cli> | ||
| ==== To disable NetworkManager, use: ==== | ==== To disable NetworkManager, use: ==== | ||
| Stop the running service: | Stop the running service: | ||
| - | systemctl is-active network.service && \ | + | <cli prompt='$'> |
| - | systemctl stop network.service | + | $ systemctl is-active network.service && \ |
| + | systemctl stop network.service | ||
| + | </cli> | ||
| Disable the NetworkManager service: | Disable the NetworkManager service: | ||
| - | systemctl disable NetworkManager.service | + | <cli prompt='$'> |
| + | $ systemctl disable NetworkManager.service | ||
| + | </cli> | ||
| Start the /etc/init.d/network service: | Start the /etc/init.d/network service: | ||
| - | systemctl start network.service | + | <cli prompt='$'> |
| + | $ systemctl start network.service | ||
| + | </cli> | ||
| all active and failed services: | all active and failed services: | ||
| - | systemctl list-units --type service --state running,failed | + | <cli prompt='$'> |
| - | | + | $ systemctl list-units --type service --state running,failed |
| + | </cli> | ||
| ==== To query the currently selected service, use: ==== | ==== To query the currently selected service, use: ==== | ||
| - | <code> | + | <cli prompt='#'> |
| graphite:~ # systemctl status network.service | graphite:~ # systemctl status network.service | ||
| NetworkManager.service - Network Manager | NetworkManager.service - Network Manager | ||
| Line 151: | Line 164: | ||
| Active: inactive (dead) | Active: inactive (dead) | ||
| CGroup: name=systemd:/system/NetworkManager.service | CGroup: name=systemd:/system/NetworkManager.service | ||
| - | </code> | + | </cli> |
| ==== Start / Stop a service ==== | ==== Start / Stop a service ==== | ||
| - | | + | |
| - | sytemctl stop network.service | + | <cli prompt='#'> |
| - | sytemctl start network.service | + | # sytemctl stop network.service |
| - | sytemctl status network.service | + | # sytemctl start network.service |
| + | # sytemctl status network.service | ||
| + | </cli> | ||
| | | ||
| ==== Create a new service ==== | ==== Create a new service ==== | ||
| Line 220: | Line 235: | ||
| It should then start automatically after rebooting the machine. | It should then start automatically after rebooting the machine. | ||
| + | |||
| + | List service dependancy | ||
| + | <cli prompt='#'> | ||
| + | [root@lnx01 system]# systemctl list-dependencies boot.mount | ||
| + | boot.mount | ||
| + | ● ├─-.mount | ||
| + | ● ├─dev-disk-by\x2duuid-3d0d7370\x2d3c77\x2d462a\x2d86a6\x2dd160d54a7fa6.device | ||
| + | ● ├─system.slice | ||
| + | ● └─systemd-fsck@dev-disk-by\x2duuid-3d0d7370\x2d3c77\x2d462a\x2d86a6\x2dd160d54a7fa6.service | ||
| + | </cli> | ||
| + | |||
| + | Add a dependancy to start after network and local filesystem mount | ||
| + | <cli prompt='#'> | ||
| + | [root@lnx01 system]# cat /etc/systemd/system/keycloak.service | ||
| + | [Unit] | ||
| + | Description=keycloak | ||
| + | After=network.target local-fs.target | ||
| + | Requires=local-fs.target | ||
| + | |||
| + | [Service] | ||
| + | #Type=idle | ||
| + | Type=forking | ||
| + | #User=keycloak | ||
| + | #Group=keycloak | ||
| + | ExecStart=/usr/lib/systemd/system/keycloak start | ||
| + | TimeoutStartSec=600 | ||
| + | TimeoutStopSec=600 | ||
| + | |||
| + | [Install] | ||
| + | WantedBy=multi-user.target | ||
| + | </cli> | ||
| ==== Change default target to boot (runlevel) ==== | ==== Change default target to boot (runlevel) ==== | ||
| Line 293: | Line 339: | ||
| ==== Systemd analyse ==== | ==== Systemd analyse ==== | ||
| + | |||
| <cli prompt='#'> | <cli prompt='#'> | ||
| # systemd-analyze | # systemd-analyze | ||
| Line 322: | Line 369: | ||
| └─network.target @31.558s | └─network.target @31.558s | ||
| └─network.service @30.819s +738ms | └─network.service @30.819s +738ms | ||
| + | </cli> | ||
| + | |||
| + | |||
| + | |||
| + | Realtime stats for services | ||
| + | <cli prompt='#'> | ||
| + | [root@lnx01 system]# systemd-cgtop | ||
| + | Control Group Tasks %CPU Memory Input/s Output/s | ||
| + | / 918 - 4.8G - - | ||
| + | /system.slice 678 - 3.6G - - | ||
| + | /system.slice/NetworkManager.service 3 - 33.2M - - | ||
| + | /system.slice/abrt-oops.service 1 - 11.0M - - | ||
| + | /system.slice/abrt-xorg.service 1 - 11.1M - - | ||
| + | /system.slice/abrtd.service 3 - 21.6M - - | ||
| + | /system.slice/atd.service 1 - 2.8M - - | ||
| + | ... | ||
| + | </cli> | ||
| + | |||
| + | Journal config file (2 ways to list it) | ||
| + | <cli prompt='#'> | ||
| + | [root@lnx01 system]# cat /etc/systemd/journald.conf | ||
| + | [root@lnx01 system]# systemd-analyze cat-config systemd/journald.conf | ||
| + | [Journal] | ||
| + | Storage=persistent | ||
| + | Compress=yes | ||
| + | #Seal=yes | ||
| + | #SplitMode=uid | ||
| + | #SyncIntervalSec=5m | ||
| + | #RateLimitIntervalSec=30s | ||
| + | #RateLimitBurst=10000 | ||
| + | #SystemMaxUse= | ||
| + | #SystemKeepFree= | ||
| + | #SystemMaxFileSize= | ||
| + | #SystemMaxFiles=100 | ||
| + | #RuntimeMaxUse= | ||
| + | #RuntimeKeepFree= | ||
| + | #RuntimeMaxFileSize= | ||
| + | #RuntimeMaxFiles=100 | ||
| + | #MaxRetentionSec= | ||
| + | MaxFileSec=1month | ||
| + | </cli> | ||
| + | |||
| + | ====== Manage service with System V (5) ====== | ||
| + | |||
| + | Old way to define a service, based on runlevel. Still used by some linux distribution, but most used Systemd. | ||
| + | |||
| + | List all services | ||
| + | <cli prompt='#'> | ||
| + | [root@lnx01 system]# chkconfig --list | ||
| + | |||
| + | Note: This output shows SysV services only and does not include native | ||
| + | systemd services. SysV configuration data might be overridden by native | ||
| + | systemd configuration. | ||
| + | |||
| + | If you want to list systemd services use 'systemctl list-unit-files'. | ||
| + | To see services enabled on particular target use | ||
| + | 'systemctl list-dependencies [target]'. | ||
| + | |||
| + | keycloak-homol 0:off 1:off 2:on 3:on 4:on 5:on 6:off | ||
| + | keycloak-labo 0:off 1:off 2:on 3:on 4:on 5:on 6:off | ||
| + | keycloak-recette 0:off 1:off 2:on 3:on 4:on 5:on 6:off | ||
| + | </cli> | ||
| + | |||
| + | Status of a service | ||
| + | <cli prompt='#'> | ||
| + | # service sshd status | ||
| + | # service --status-all | ||
| + | </cli> | ||
| + | |||
| + | enable or disable | ||
| + | <cli prompt='#'> | ||
| + | # chkconfig httpd off | ||
| + | # chkconfig ntpd on | ||
| + | </cli> | ||
| + | |||
| + | enable for specific level | ||
| + | <cli prompt='#'> | ||
| + | # chkconfig --level 3,4 ntpd on | ||
| + | </cli> | ||
| + | |||
| + | Add or delete a service | ||
| + | <cli prompt='#'> | ||
| + | # chkconfig add rhnsd | ||
| + | # chkconfig del rhnsd | ||
| </cli> | </cli> | ||
linux/linux_systemd.1636124611.txt.gz · Last modified: 2021/11/05 16:03 by manu
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