[CentOS 7.0] Configure Services

[1] Configure Services of the System.

# list services which are booted (list all includes inactive one with “–all” option)

[root@dlp ~]#systemctl -t service

UNIT                                    LOAD   ACTIVE SUB     DESCRIPTION
auditd.service                      loaded active running Security Auditing Service
avahi-daemon.service         loaded active running Avahi mDNS/DNS-SD Stack
crond.service                       loaded active running Command Scheduler
dbus.service                        loaded active running D-Bus System Message Bus
getty@tty1.service               loaded active running Getty on tty1
…
…
…
systemd-udevd.service                   loaded active running udev Kernel Device Manager
systemd-update-utmp.service             loaded active exited  Update UTMP about System Reboot/Shutdown
systemd-user-sessions.service           loaded active exited  Permit User Sessions
systemd-vconsole-setup.service          loaded active exited  Setup Virtual Console
tuned.service                           loaded active running Dynamic System Tuning Daemon

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

37 loaded units listed. Pass –all to see loaded but inactive units, too.
To show all installed unit files use ‘systemctl list-unit-files’.

# list boot config of services
[root@dlp ~]#systemctl list-unit-files -t service

UNIT FILE                              STATE
arp-ethers.service                     disabled
auditd.service                         enabled
autovt@.service                        disabled
avahi-daemon.service                   enabled
blk-availability.service               disabled
…
…
…
systemd-user-sessions.service          static
systemd-vconsole-setup.service         static
teamd@.service                         static
tuned.service                          enabled
wpa_supplicant.service                 disabled

124 unit files listed.

[2] Stop and turn OFF auto-start setting for a service if you don’d need it. (it’s postfix as an example below)

[root@dlp ~]#systemctl stop postfix

[root@dlp ~]#systemctl disable postfix
rm ‘/etc/systemd/system/multi-user.target.wants/postfix.service’

[3] There are some SysV services yet. Those are controled by chkconfig like below.

[root@dlp ~]#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]’.

iprdump         0:off   1:off   2:on    3:on    4:on    5:on    6:off
iprinit         0:off   1:off   2:on    3:on    4:on    5:on    6:off
iprupdate       0:off   1:off   2:on    3:on    4:on    5:on    6:off
netconsole      0:off   1:off   2:off   3:off   4:off   5:off   6:off
network         0:off   1:off   2:on    3:on    4:on    5:on    6:off

# for exmaple, turn OFF auto-start for netconsole

[root@dlp ~]#chkconfig netconsole off