1. RHEL 7 booting process. -> page 266, 277
2. To Poweroff machine or reboot it:
[root@server0 ~]# systemctl poweroff
[root@server0 ~]# systemctl reboot
3. 'poweroff' and 'reboot' commands are still there but has symbolic links to the new command 'systemctl':
[root@server0 ~]# ls -lh /sbin/poweroff
lrwxrwxrwx. 1 root root 16 May 7 2014 /sbin/poweroff -> ../bin/systemctl
[root@server0 ~]# ls -lh /sbin/reboot
lrwxrwxrwx. 1 root root 16 May 7 2014 /sbin/reboot -> ../bin/systemctl
4. Defenation of 'systemctl halt' as in pager 267:
[root@server0 ~]# systemctl halt
Result:
You can now Poweroff the machine manually:
[root@server0 ~]# ls -lh /sbin/halt
lrwxrwxrwx. 1 root root 16 May 7 2014 /sbin/halt -> ../bin/systemctl
5. 'systemd target' dfination -> page 267,268
List current
active 'systemd target':
[root@server0 ~]# systemctl list-units --type help
Available unit types:
service
socket
target
device
mount
automount
snapshot
timer
swap
path
slice
scope
[root@server0 ~]# systemctl list-units --type=target
UNIT LOAD ACTIVE SUB DESCRIPTION
basic.target loaded active active Basic System
cryptsetup.target loaded active active Encrypted Volumes
getty.target loaded active active Login Prompts
graphical.target loaded active active Graphical Interface
local-fs-pre.target loaded active active Local File Systems (Pre)
local-fs.target loaded active active Local File Systems
multi-user.target loaded active active Multi-User System
network.target loaded active active Network
nfs.target loaded active active Network File System Server
paths.target loaded active active Paths
remote-fs.target loaded active active Remote File Systems
slices.target loaded active active Slices
sockets.target loaded active active Sockets
swap.target loaded active active Swap
sysinit.target loaded active active System Initialization
timers.target loaded active active Timers
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.
16 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
You can found it also in '/etc/systemd/system' dir:
root@server0 ~]# ls -lh /etc/systemd/system
total 12K
drwxr-xr-x. 2 root root 54 Jul 11 2014 basic.target.wants
drwxr-xr-x. 2 root root 30 Jul 11 2014 bluetooth.target.wants
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.bluez.service -> /usr/lib/systemd/system/bluetooth.service
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.fedoraproject.FirewallD1.service -> /usr/lib/systemd/system/firewalld.service
lrwxrwxrwx. 1 root root 44 May 7 2014 dbus-org.freedesktop.Avahi.service -> /usr/lib/systemd/system/avahi-daemon.service
lrwxrwxrwx. 1 root root 44 Jul 11 2014 dbus-org.freedesktop.ModemManager1.service -> /usr/lib/systemd/system/ModemManager.service
lrwxrwxrwx. 1 root root 46 May 7 2014 dbus-org.freedesktop.NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service
lrwxrwxrwx. 1 root root 57 May 7 2014 dbus-org.freedesktop.nm-dispatcher.service -> /usr/lib/systemd/system/NetworkManager-dispatcher.service
lrwxrwxrwx. 1 root root 40 Jul 11 2014 default.target -> /usr/lib/systemd/system/graphical.target
drwxr-xr-x. 2 root root 85 May 7 2014 default.target.wants
lrwxrwxrwx. 1 root root 35 Jul 11 2014 display-manager.service -> /usr/lib/systemd/system/gdm.service
drwxr-xr-x. 2 root root 31 May 7 2014 getty.target.wants
drwxr-xr-x. 2 root root 63 Jul 11 2014 graphical.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 multi-user.target.wants
drwxr-xr-x. 2 root root 29 May 7 2014 nfs.target.wants
drwxr-xr-x. 2 root root 25 Jul 11 2014 printer.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sockets.target.wants
drwxr-xr-x. 2 root root 35 Jul 11 2014 spice-vdagentd.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sysinit.target.wants
drwxr-xr-x. 2 root root 83 Jul 11 2014 system-update.target.wants
lrwxrwxrwx. 1 root root 9 May 7 2014 tmp.mount -> /dev/null
List
all 'systemd target':
[root@server0 ~]# systemctl list-units --type=target --all
UNIT LOAD ACTIVE SUB DESCRIPTION
basic.target loaded active active Basic System
cryptsetup.target loaded active active Encrypted Volumes
emergency.target loaded inactive dead Emergency Mode
final.target loaded inactive dead Final Step
getty.target loaded active active Login Prompts
graphical.target loaded active active Graphical Interface
local-fs-pre.target loaded active active Local File Systems (Pre)
local-fs.target loaded active active Local File Systems
multi-user.target loaded active active Multi-User System
network-online.target loaded inactive dead Network is Online
network.target loaded active active Network
nfs.target loaded active active Network File System Server
nss-lookup.target loaded inactive dead Host and Network Name Lookups
nss-user-lookup.target loaded inactive dead User and Group Name Lookups
paths.target loaded active active Paths
remote-fs-pre.target loaded inactive dead Remote File Systems (Pre)
remote-fs.target loaded active active Remote File Systems
rescue.target loaded inactive dead Rescue Mode
shutdown.target loaded inactive dead Shutdown
slices.target loaded active active Slices
sockets.target loaded active active Sockets
swap.target loaded active active Swap
sysinit.target loaded active active System Initialization
syslog.target not-found inactive dead syslog.target
time-sync.target loaded inactive dead System Time Synchronized
timers.target loaded active active Timers
umount.target loaded inactive dead Unmount All Filesystems
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.
27 loaded units listed.
To show all installed unit files use 'systemctl list-unit-files'.
IMPORTANT:
Main'systemd target' defination can be found in
[root@server0 ~]# man systemd.special
[root@server0 ~]# man systemd.target
To be reviewed:
[root@server0 ~]# systemctl list-unit-files --type=target
[root@server0 ~]# systemctl list-unit-files --type=target --all
6. List dependancies of 'systemd target':
[root@server0 ~]# systemctl list-dependencies graphical.target | grep target
graphical.target
└─multi-user.target
├─basic.target
│ ├─paths.target
│ ├─slices.target
│ ├─sockets.target
│ ├─sysinit.target
│ │ ├─cryptsetup.target
│ │ ├─local-fs.target
│ │ └─swap.target
│ └─timers.target
├─getty.target
├─nfs.target
└─remote-fs.target
7. Selecting 'systemd target' at runtime:
Following command is some sort equal to 'init 3':
[root@server0 ~]# systemctl isolate multi-user.target
8. Find default 'systemd target' using 'systemctl get-default' command line or by exploaring '/etc/systemd/system' dir:
[root@server0 ~]# systemctl get-default
graphical.target
[root@server0 ~]# ls -lh /etc/systemd/system
total 12K
drwxr-xr-x. 2 root root 54 Jul 11 2014 basic.target.wants
drwxr-xr-x. 2 root root 30 Jul 11 2014 bluetooth.target.wants
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.bluez.service -> /usr/lib/systemd/system/bluetooth.service
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.fedoraproject.FirewallD1.service -> /usr/lib/systemd/system/firewalld.service
lrwxrwxrwx. 1 root root 44 May 7 2014 dbus-org.freedesktop.Avahi.service -> /usr/lib/systemd/system/avahi-daemon.service
lrwxrwxrwx. 1 root root 44 Jul 11 2014 dbus-org.freedesktop.ModemManager1.service -> /usr/lib/systemd/system/ModemManager.service
lrwxrwxrwx. 1 root root 46 May 7 2014 dbus-org.freedesktop.NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service
lrwxrwxrwx. 1 root root 57 May 7 2014 dbus-org.freedesktop.nm-dispatcher.service -> /usr/lib/systemd/system/NetworkManager-dispatcher.service
lrwxrwxrwx. 1 root root 40 Jul 11 2014 default.target -> /usr/lib/systemd/system/graphical.target
drwxr-xr-x. 2 root root 85 May 7 2014 default.target.wants
lrwxrwxrwx. 1 root root 35 Jul 11 2014 display-manager.service -> /usr/lib/systemd/system/gdm.service
drwxr-xr-x. 2 root root 31 May 7 2014 getty.target.wants
drwxr-xr-x. 2 root root 63 Jul 11 2014 graphical.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 multi-user.target.wants
drwxr-xr-x. 2 root root 29 May 7 2014 nfs.target.wants
drwxr-xr-x. 2 root root 25 Jul 11 2014 printer.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sockets.target.wants
drwxr-xr-x. 2 root root 35 Jul 11 2014 spice-vdagentd.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sysinit.target.wants
drwxr-xr-x. 2 root root 83 Jul 11 2014 system-update.target.wants
lrwxrwxrwx. 1 root root 9 May 7 2014 tmp.mount -> /dev/null
9. Set Default 'systemd target':
[root@server0 ~]# systemctl get-default
graphical.target
[root@server0 ~]# ls -lh /etc/systemd/system
total 12K
drwxr-xr-x. 2 root root 54 Jul 11 2014 basic.target.wants
drwxr-xr-x. 2 root root 30 Jul 11 2014 bluetooth.target.wants
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.bluez.service -> /usr/lib/systemd/system/bluetooth.service
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.fedoraproject.FirewallD1.service -> /usr/lib/systemd/system/firewalld.service
lrwxrwxrwx. 1 root root 44 May 7 2014 dbus-org.freedesktop.Avahi.service -> /usr/lib/systemd/system/avahi-daemon.service
lrwxrwxrwx. 1 root root 44 Jul 11 2014 dbus-org.freedesktop.ModemManager1.service -> /usr/lib/systemd/system/ModemManager.service
lrwxrwxrwx. 1 root root 46 May 7 2014 dbus-org.freedesktop.NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service
lrwxrwxrwx. 1 root root 57 May 7 2014 dbus-org.freedesktop.nm-dispatcher.service -> /usr/lib/systemd/system/NetworkManager-dispatcher.service
lrwxrwxrwx. 1 root root 40 Jul 11 2014 default.target -> /usr/lib/systemd/system/graphical.target
drwxr-xr-x. 2 root root 85 May 7 2014 default.target.wants
lrwxrwxrwx. 1 root root 35 Jul 11 2014 display-manager.service -> /usr/lib/systemd/system/gdm.service
drwxr-xr-x. 2 root root 31 May 7 2014 getty.target.wants
drwxr-xr-x. 2 root root 63 Jul 11 2014 graphical.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 multi-user.target.wants
drwxr-xr-x. 2 root root 29 May 7 2014 nfs.target.wants
drwxr-xr-x. 2 root root 25 Jul 11 2014 printer.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sockets.target.wants
drwxr-xr-x. 2 root root 35 Jul 11 2014 spice-vdagentd.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sysinit.target.wants
drwxr-xr-x. 2 root root 83 Jul 11 2014 system-update.target.wants
lrwxrwxrwx. 1 root root 9 May 7 2014 tmp.mount -> /dev/null
[root@server0 ~]# systemctl list-units --type=target
UNIT LOAD ACTIVE SUB DESCRIPTION
basic.target loaded active active Basic System
cryptsetup.target loaded active active Encrypted Volumes
getty.target loaded active active Login Prompts
local-fs-pre.target loaded active active Local File Systems (Pre)
local-fs.target loaded active active Local File Systems
multi-user.target loaded active active Multi-User System
network.target loaded active active Network
nfs.target loaded active active Network File System Server
paths.target loaded active active Paths
remote-fs.target loaded active active Remote File Systems
slices.target loaded active active Slices
sockets.target loaded active active Sockets
swap.target loaded active active Swap
sysinit.target loaded active active System Initialization
timers.target loaded active active Timers
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.
15 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.
[root@server0 ~]# systemctl set-default multi-user.target
rm '/etc/systemd/system/default.target'
ln -s '/usr/lib/systemd/system/multi-user.target' '/etc/systemd/system/default.target'
[root@server0 ~]# systemctl get-default
multi-user.target
[root@server0 ~]# ls -lh /etc/systemd/system
total 12K
drwxr-xr-x. 2 root root 54 Jul 11 2014 basic.target.wants
drwxr-xr-x. 2 root root 30 Jul 11 2014 bluetooth.target.wants
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.bluez.service -> /usr/lib/systemd/system/bluetooth.service
lrwxrwxrwx. 1 root root 41 Jul 11 2014 dbus-org.fedoraproject.FirewallD1.service -> /usr/lib/systemd/system/firewalld.service
lrwxrwxrwx. 1 root root 44 May 7 2014 dbus-org.freedesktop.Avahi.service -> /usr/lib/systemd/system/avahi-daemon.service
lrwxrwxrwx. 1 root root 44 Jul 11 2014 dbus-org.freedesktop.ModemManager1.service -> /usr/lib/systemd/system/ModemManager.service
lrwxrwxrwx. 1 root root 46 May 7 2014 dbus-org.freedesktop.NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service
lrwxrwxrwx. 1 root root 57 May 7 2014 dbus-org.freedesktop.nm-dispatcher.service -> /usr/lib/systemd/system/NetworkManager-dispatcher.service
lrwxrwxrwx. 1 root root 41 Feb 25 06:29 default.target -> /usr/lib/systemd/system/multi-user.target
drwxr-xr-x. 2 root root 85 May 7 2014 default.target.wants
lrwxrwxrwx. 1 root root 35 Jul 11 2014 display-manager.service -> /usr/lib/systemd/system/gdm.service
drwxr-xr-x. 2 root root 31 May 7 2014 getty.target.wants
drwxr-xr-x. 2 root root 63 Jul 11 2014 graphical.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 multi-user.target.wants
drwxr-xr-x. 2 root root 29 May 7 2014 nfs.target.wants
drwxr-xr-x. 2 root root 25 Jul 11 2014 printer.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sockets.target.wants
drwxr-xr-x. 2 root root 35 Jul 11 2014 spice-vdagentd.target.wants
drwxr-xr-x. 2 root root 4.0K Jul 11 2014 sysinit.target.wants
drwxr-xr-x. 2 root root 83 Jul 11 2014 system-update.target.wants
lrwxrwxrwx. 1 root root 9 May 7 2014 tmp.mount -> /dev/null
To be reviewd:
==========
1. 'info grub2', 'man sulogin', 'man dracut.bootup' -> page 69
2. 'man bootup' -> important.
