Quản lý và Cấu hình các dịch vụ bằng systemctl trên Centos 7

[1] It's possible to make sure services' status like follows.
# display the list of services which are running

[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.

39 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

# the list of all services

[root@dlp ~]# systemctl list-unit-files -t service 

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

125 unit files listed.

[2] Stop and turn OFF auto-start setting for a service if you don'd need it. (it's smartd 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 follows. 

[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 setting for netconsole
[root@dlp ~]# chkconfig netconsole off