To list all service
[root@rhel1 ~]# systemctl list-units --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION
abrt-ccpp.service loaded active exited Install ABRT coredump hook
abrt-oops.service loaded active running ABRT kernel log watcher
abrt-xorg.service loaded active running ABRT Xorg log watcher
abrtd.service loaded active running ABRT Automated Bug Reporting Tool
atd.service loaded active running Job spooling too
To list all Failed service
[root@rhel1 ~]# systemctl --failed
UNIT LOAD ACTIVE SUB DESCRIPTION
● kdump.service loaded failed failed Crash recovery kernel arming
● mcelog.service loaded failed failed Machine Check Exception Logging Daemon
To list all Failed dependencies service
[root@rhel1 ~]# systemctl list-dependencies rsyslog
rsyslog.service
● ├─system.slice
● ├─basic.target
● │ ├─microcode.service
● │ ├─rhel-dmesg.service
to check active service
[root@rhel1 ~]# systemctl is-active rsyslog
unknown
[root@rhel1 ~]#
[root@rhel1 ~]#
to check enabled service
[root@rhel1 ~]# systemctl is-enabled rsyslog
disabled
[root@rhel1 ~]#
[root@rhel1 ~]#
to enable service
[root@rhel1 ~]# systemctl enable rsyslog
Created symlink from /etc/systemd/system/multi-user.target.wants/rsyslog.service to /usr/lib/systemd/system/rsyslog.service.
[root@rhel1 ~]#
[root@rhel1 ~]#
to check enable status of service
[root@rhel1 ~]# systemctl is-enabled rsyslog
enabled
[root@rhel1 ~]#
[root@rhel1 ~]#
to check active status of service
[root@rhel1 ~]# systemctl is-active rsyslog
inactive
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]#
To start service
[root@rhel1 ~]# systemctl start rsyslog
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl is-active rsyslog
active
[root@rhel1 ~]#
[root@rhel1 ~]#
to reload service
[root@rhel1 ~]# systemctl reload rsyslog
Failed to reload rsyslog.service: Job type reload is not applicable for unit rsyslog.service.
See system logs and 'systemctl status rsyslog.service' for details.
[root@rhel1 ~]#
to restart service
[root@rhel1 ~]# systemctl restart rsyslog
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl status rsyslog.service
● rsyslog.service - System Logging Service
Loaded: loaded (/usr/lib/systemd/system/rsyslog.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-09-13 20:44:35 IST; 13s ago
Docs: man:rsyslogd(8)
http://www.rsyslog.com/doc/
Main PID: 67310 (rsyslogd)
CGroup: /system.slice/rsyslog.service
└─67310 /usr/sbin/rsyslogd -n
Sep 13 20:44:30 rhel1 systemd[1]: Stopped System Logging Service.
Sep 13 20:44:30 rhel1 systemd[1]: Starting System Logging Service...
Sep 13 20:44:35 rhel1 rsyslogd[67310]: [origin software="rsyslogd" swVersion="8.24.0-38.el7" x-pid="67310" x-info="http://www.rsyslog.com"] start
Sep 13 20:44:35 rhel1 systemd[1]: Started System Logging Service.
to set default targets:
[root@rhel1 ~]# systemctl set-default rescue.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/rescue.target.
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl get-default
rescue.target
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl set-default poweroff.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/poweroff.target.
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl set-default multi-user.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl set-default network
network-online.target network-pre.target network.target
[root@rhel1 ~]# systemctl set-default network
network-online.target network-pre.target network.target
[root@rhel1 ~]# systemctl set-default network.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/network.target.
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl set-default graphical.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/graphical.target.
[root@rhel1 ~]#
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl set-default multi-user.target
Removed symlink /etc/systemd/system/default.target.
Created symlink from /etc/systemd/system/default.target to /usr/lib/systemd/system/multi-user.target.
[root@rhel1 ~]#
[root@rhel1 ~]# systemctl get-default
multi-user.target
[root@rhel1 ~]#