Linux7（CentOS,RHEL,OEL）和Oracle RAC环境系列–4-target（图形界面和字符界面）

[root@lunar system]# ll /etc/systemd/system/|grep ohasd -rw-r--r--  1 root root  361 Oct  9 12:29 oracle-ohasd.service [root@lunar system]#  [root@lunar system]# ll /etc/systemd/system/ total 16 drwxr-xr-x. 2 root root   30 Oct  8 07:17 basic.target.wants drwxr-xr-x. 2 root root   30 Oct  7 23:08 bluetooth.target.wants lrwxrwxrwx. 1 root root   41 Oct  7 23:08 dbus-org.bluez.service -> /usr/lib/systemd/system/bluetooth.service lrwxrwxrwx. 1 root root   44 Oct  7 23:10 dbus-org.freedesktop.ModemManager1.service -> /usr/lib/systemd/system/ModemManager.service lrwxrwxrwx. 1 root root   46 Oct  7 23:04 dbus-org.freedesktop.NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service lrwxrwxrwx. 1 root root   57 Oct  7 23:04 dbus-org.freedesktop.nm-dispatcher.service -> /usr/lib/systemd/system/NetworkManager-dispatcher.service lrwxrwxrwx  1 root root   41 Oct  8 16:51 default.target -> /usr/lib/systemd/system/multi-user.target drwxr-xr-x. 2 root root   85 Oct  7 23:02 default.target.wants lrwxrwxrwx. 1 root root   35 Oct  7 23:08 display-manager.service -> /usr/lib/systemd/system/gdm.service drwxr-xr-x. 2 root root   31 Oct  7 23:02 getty.target.wants drwxr-xr-x. 2 root root   90 Oct  9 12:29 graphical.target.wants drwxr-xr-x. 2 root root 4096 Oct  9 12:29 multi-user.target.wants lrwxrwxrwx. 1 root root   38 Oct  7 23:04 mysql.service -> /usr/lib/systemd/system/mysqld.service -rw-r--r--  1 root root  361 Oct  9 12:29 oracle-ohasd.service drwxr-xr-x. 2 root root   25 Oct  7 23:05 printer.target.wants drwxr-xr-x. 2 root root 4096 Oct  8 07:32 sockets.target.wants drwxr-xr-x. 2 root root   35 Oct  7 23:10 spice-vdagentd.target.wants drwxr-xr-x. 2 root root 4096 Oct  8 22:19 sysinit.target.wants drwxr-xr-x. 2 root root   83 Oct  7 23:05 system-update.target.wants [root@lunar system]#

基本target中，只有微码服务：

[root@lunar1 ~]# ll /etc/systemd/system/basic.target.wants 总用量 0 lrwxrwxrwx. 1 root root 41 1月  16 03:00 microcode.service -> /usr/lib/systemd/system/microcode.service [root@lunar1 ~]#

sysinit的目标：

[root@lunar1 ~]# ll /etc/systemd/system/sysinit.target.wants 总用量 0 lrwxrwxrwx. 1 root root 49 1月  16 02:57 dmraid-activation.service -> /usr/lib/systemd/system/dmraid-activation.service lrwxrwxrwx. 1 root root 37 1月  16 02:53 iscsi.service -> /usr/lib/systemd/system/iscsi.service lrwxrwxrwx. 1 root root 43 1月  16 02:54 lvm2-lvmetad.socket -> /usr/lib/systemd/system/lvm2-lvmetad.socket lrwxrwxrwx. 1 root root 44 1月  16 02:54 lvm2-lvmpolld.socket -> /usr/lib/systemd/system/lvm2-lvmpolld.socket lrwxrwxrwx. 1 root root 44 1月  16 02:54 lvm2-monitor.service -> /usr/lib/systemd/system/lvm2-monitor.service lrwxrwxrwx. 1 root root 42 1月  16 02:56 multipathd.service -> /usr/lib/systemd/system/multipathd.service [root@lunar1 ~]#

缺省目标：

[root@lunar1 ~]# ll /etc/systemd/system/default.target.wants 总用量 0 lrwxrwxrwx. 1 root root 57 1月  16 02:52 systemd-readahead-collect.service -> /usr/lib/systemd/system/systemd-readahead-collect.service lrwxrwxrwx. 1 root root 56 1月  16 02:52 systemd-readahead-replay.service -> /usr/lib/systemd/system/systemd-readahead-replay.service [root@lunar1 ~]#

多用户字符界面的目标（runlevel 3）：

[root@lunar1 ~]# ll /etc/systemd/system/multi-user.target.wants/ 总用量 0 lrwxrwxrwx. 1 root root 41 1月  16 02:54 abrt-ccpp.service -> /usr/lib/systemd/system/abrt-ccpp.service lrwxrwxrwx. 1 root root 37 1月  16 02:53 abrtd.service -> /usr/lib/systemd/system/abrtd.service lrwxrwxrwx. 1 root root 41 1月  16 02:53 abrt-oops.service -> /usr/lib/systemd/system/abrt-oops.service lrwxrwxrwx. 1 root root 43 1月  16 02:54 abrt-vmcore.service -> /usr/lib/systemd/system/abrt-vmcore.service lrwxrwxrwx. 1 root root 41 1月  16 02:53 abrt-xorg.service -> /usr/lib/systemd/system/abrt-xorg.service lrwxrwxrwx. 1 root root 35 1月  16 03:01 atd.service -> /usr/lib/systemd/system/atd.service lrwxrwxrwx. 1 root root 39 1月  16 02:56 chronyd.service -> /usr/lib/systemd/system/chronyd.service lrwxrwxrwx. 1 root root 37 1月  16 02:53 crond.service -> /usr/lib/systemd/system/crond.service lrwxrwxrwx. 1 root root 42 1月  16 02:55 hypervkvpd.service -> /usr/lib/systemd/system/hypervkvpd.service lrwxrwxrwx. 1 root root 42 1月  16 02:55 hypervvssd.service -> /usr/lib/systemd/system/hypervvssd.service lrwxrwxrwx. 1 root root 42 1月  16 03:01 irqbalance.service -> /usr/lib/systemd/system/irqbalance.service lrwxrwxrwx. 1 root root 37 1月  16 02:54 kdump.service -> /usr/lib/systemd/system/kdump.service lrwxrwxrwx. 1 root root 35 1月  16 02:56 ksm.service -> /usr/lib/systemd/system/ksm.service lrwxrwxrwx. 1 root root 40 1月  16 02:56 ksmtuned.service -> /usr/lib/systemd/system/ksmtuned.service lrwxrwxrwx. 1 root root 46 1月  16 02:54 libstoragemgmt.service -> /usr/lib/systemd/system/libstoragemgmt.service lrwxrwxrwx. 1 root root 40 1月  16 02:54 libvirtd.service -> /usr/lib/systemd/system/libvirtd.service lrwxrwxrwx. 1 root root 41 1月  16 02:53 mdmonitor.service -> /usr/lib/systemd/system/mdmonitor.service lrwxrwxrwx. 1 root root 44 1月  16 03:02 ModemManager.service -> /usr/lib/systemd/system/ModemManager.service lrwxrwxrwx. 1 root root 46 1月  16 02:55 NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service lrwxrwxrwx. 1 root root 41 1月  16 02:56 nfs-client.target -> /usr/lib/systemd/system/nfs-client.target lrwxrwxrwx. 1 root root 39 1月  16 02:55 postfix.service -> /usr/lib/systemd/system/postfix.service lrwxrwxrwx. 1 root root 40 1月  16 02:52 remote-fs.target -> /usr/lib/systemd/system/remote-fs.target lrwxrwxrwx. 1 root root 36 1月  16 03:01 rngd.service -> /usr/lib/systemd/system/rngd.service lrwxrwxrwx. 1 root root 39 1月  16 02:56 rsyslog.service -> /usr/lib/systemd/system/rsyslog.service lrwxrwxrwx. 1 root root 36 1月  16 03:01 sshd.service -> /usr/lib/systemd/system/sshd.service lrwxrwxrwx. 1 root root 39 1月  16 02:54 sysstat.service -> /usr/lib/systemd/system/sysstat.service lrwxrwxrwx. 1 root root 40 1月  16 02:53 vmtoolsd.service -> /usr/lib/systemd/system/vmtoolsd.service [root@lunar1 ~]#

而/usr/lib/systemd/system下面定义的unit就太多了：

[root@lunar1 ~]# ls -lrt /usr/lib/systemd/system/|wc -l 404 [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep graphical -rw-r--r--. 1 root root     469 3月   3 2014 firstboot-graphical.service -rw-r--r--. 1 root root     558 11月 20 12:49 graphical.target lrwxrwxrwx. 1 root root      16 1月  16 02:52 default.target -> graphical.target drwxr-xr-x. 2 root root      49 1月  16 02:52 graphical.target.wants lrwxrwxrwx. 1 root root      16 1月  16 02:52 runlevel5.target -> graphical.target [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep multi -rw-r--r--. 1 root root     492 11月 20 12:49 multi-user.target -rw-r--r--. 1 root root     597 11月 20 23:34 multipathd.service lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel2.target -> multi-user.target lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel3.target -> multi-user.target lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel4.target -> multi-user.target drwxr-xr-x. 2 root root    4096 1月  16 02:53 multi-user.target.wants [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep runlevel -rw-r--r--. 1 root root     761 11月 20 12:49 systemd-update-utmp-runlevel.service lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel2.target -> multi-user.target drwxr-xr-x. 2 root root      49 1月  16 02:52 runlevel1.target.wants lrwxrwxrwx. 1 root root      13 1月  16 02:52 runlevel1.target -> rescue.target lrwxrwxrwx. 1 root root      15 1月  16 02:52 runlevel0.target -> poweroff.target lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel3.target -> multi-user.target drwxr-xr-x. 2 root root      49 1月  16 02:52 runlevel2.target.wants drwxr-xr-x. 2 root root      49 1月  16 02:52 runlevel4.target.wants lrwxrwxrwx. 1 root root      17 1月  16 02:52 runlevel4.target -> multi-user.target drwxr-xr-x. 2 root root      49 1月  16 02:52 runlevel3.target.wants lrwxrwxrwx. 1 root root      13 1月  16 02:52 runlevel6.target -> reboot.target drwxr-xr-x. 2 root root      49 1月  16 02:52 runlevel5.target.wants lrwxrwxrwx. 1 root root      16 1月  16 02:52 runlevel5.target -> graphical.target [root@lunar1 ~]#  [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep NetworkManager -rw-r--r--. 1 root root     284 11月 21 00:55 NetworkManager-wait-online.service -rw-r--r--. 1 root root     419 11月 21 00:55 NetworkManager.service -rw-r--r--. 1 root root     353 11月 21 00:55 NetworkManager-dispatcher.service [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep network -rw-r--r--. 1 root root     585 11月 20 12:49 systemd-networkd.socket -rw-r--r--. 1 root root     480 11月 20 12:49 network.target -rw-r--r--. 1 root root     461 11月 20 12:49 network-pre.target -rw-r--r--. 1 root root     464 11月 20 12:49 network-online.target lrwxrwxrwx. 1 root root      24 1月  16 02:52 dbus-org.freedesktop.network1.service -> systemd-networkd.service drwxr-xr-x. 2 root root      47 1月  16 02:55 network-online.target.wants [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep rsyslog -rw-r--r--. 1 root root     288 11月 20 19:34 rsyslog.service [root@lunar1 ~]# ls -lrt /usr/lib/systemd/system|grep -v grep|grep udev -rw-r--r--. 1 root root     751 11月 20 12:49 systemd-udev-trigger.service -rw-r--r--. 1 root root     827 11月 20 12:49 systemd-udev-settle.service -rw-r--r--. 1 root root     829 11月 20 12:49 systemd-udevd.service -rw-r--r--. 1 root root     570 11月 20 12:49 systemd-udevd-kernel.socket -rw-r--r--. 1 root root     578 11月 20 12:49 systemd-udevd-control.socket -rw-r--r--. 1 root root     668 11月 20 12:49 initrd-udevadm-cleanup-db.service lrwxrwxrwx. 1 root root      56 1月  16 02:52 dracut-pre-udev.service -> ../../dracut/modules.d/98systemd/dracut-pre-udev.service [root@lunar1 ~]#

从Linux7开始，不使用inittab作为启动配置文件，其内容仅仅是个说明：

[root@lunar1 ~]# cat /etc/inittab # inittab is no longer used when using systemd. # # ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # # Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target # # systemd uses 'targets' instead of runlevels. By default, there are two main targets: # # multi-user.target: analogous to runlevel 3 # graphical.target: analogous to runlevel 5 # # To view current default target, run: # systemctl get-default # # To set a default target, run: # systemctl set-default TARGET.target # [root@lunar1 ~]#

从上面的说明不难看出，systemd不使用inittab作为配置文件，因此在这里添加的服务将不会生效systemd使用’targets’代替了runlevels，缺省有两个targets：

# multi-user.target: analogous to runlevel 3 # graphical.target: analogous to runlevel 5

[root@lunar1 ~]# 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-online.target loaded active active Network is Online network.target        loaded active active Network nfs-client.target     loaded active active NFS client services paths.target          loaded active active Paths remote-fs-pre.target  loaded active active Remote File Systems (Pre) 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.  17 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'. [root@lunar1 ~]#

查看默认target：

[root@lunar1 ~]# systemctl get-default multi-user.target [root@lunar1 ~]#

也就是当前运行在多用户字符集面的模式。查看当前所有的运行级别的定义：

[root@lunar1 ~]# ll /usr/lib/systemd/system/runlevel* lrwxrwxrwx. 1 root root 15 1月  16 02:52 /usr/lib/systemd/system/runlevel0.target -> poweroff.target lrwxrwxrwx. 1 root root 13 1月  16 02:52 /usr/lib/systemd/system/runlevel1.target -> rescue.target lrwxrwxrwx. 1 root root 17 1月  16 02:52 /usr/lib/systemd/system/runlevel2.target -> multi-user.target lrwxrwxrwx. 1 root root 17 1月  16 02:52 /usr/lib/systemd/system/runlevel3.target -> multi-user.target lrwxrwxrwx. 1 root root 17 1月  16 02:52 /usr/lib/systemd/system/runlevel4.target -> multi-user.target lrwxrwxrwx. 1 root root 16 1月  16 02:52 /usr/lib/systemd/system/runlevel5.target -> graphical.target lrwxrwxrwx. 1 root root 13 1月  16 02:52 /usr/lib/systemd/system/runlevel6.target -> reboot.target  /usr/lib/systemd/system/runlevel1.target.wants: 总用量 0 lrwxrwxrwx. 1 root root 39 1月  16 02:52 systemd-update-utmp-runlevel.service -> ../systemd-update-utmp-runlevel.service  /usr/lib/systemd/system/runlevel2.target.wants: 总用量 0 lrwxrwxrwx. 1 root root 39 1月  16 02:52 systemd-update-utmp-runlevel.service -> ../systemd-update-utmp-runlevel.service  /usr/lib/systemd/system/runlevel3.target.wants: 总用量 0 lrwxrwxrwx. 1 root root 39 1月  16 02:52 systemd-update-utmp-runlevel.service -> ../systemd-update-utmp-runlevel.service  /usr/lib/systemd/system/runlevel4.target.wants: 总用量 0 lrwxrwxrwx. 1 root root 39 1月  16 02:52 systemd-update-utmp-runlevel.service -> ../systemd-update-utmp-runlevel.service  /usr/lib/systemd/system/runlevel5.target.wants: 总用量 0 lrwxrwxrwx. 1 root root 39 1月  16 02:52 systemd-update-utmp-runlevel.service -> ../systemd-update-utmp-runlevel.service [root@lunar1 ~]#

这里我们看到了熟悉的 运行级别的身影：

runlevel0.target -> poweroff.target ---关机 runlevel1.target -> rescue.target ----营救模式 runlevel2.target -> multi-user.target  runlevel3.target -> multi-user.target ----多用户的字符界面 runlevel4.target -> multi-user.target runlevel5.target -> graphical.target ----图形界面 runlevel6.target -> reboot.target ----reboot主机

查看当前的正处在哪个target中：

[root@lunar system]# 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 paths.target         loaded active active Paths remote-fs-pre.target loaded active active Remote File Systems (Pre) 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@lunar system]#  [root@lunar system]# systemctl list-units --type=target|grep graphical [root@lunar system]#

可以看到当前处在runlevel的运行界别类似于以前的level 3 ，即字符界面启动的我们切换到图形界面启动的运行级别（类似于以前的runlevel 5）：

[root@lunar system]# systemctl isolate graphical.target [root@lunar system]# 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 paths.target         loaded active active Paths remote-fs-pre.target loaded active active Remote File Systems (Pre) 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'. [root@lunar system]#  [root@lunar system]# systemctl list-units --type=target|grep graphical graphical.target     loaded active active Graphical Interface [root@lunar system]#

这时候我们可以看到关键字：graphical.target

查看当前缺省的运行级别：

[root@lunar system]# systemctl get-default multi-user.target [root@lunar system]#

查看unit名为ohasd.serviced的依赖关系：

[root@lunar system]# systemctl list-dependencies ohasd.service ohasd.service ├─system.slice └─basic.target   ├─alsa-restore.service   ├─alsa-state.service   ├─microcode.service   ├─rhel-autorelabel-mark.service   ├─rhel-autorelabel.service   ├─rhel-configure.service   ├─rhel-dmesg.service   ├─rhel-loadmodules.service   ├─paths.target   ├─slices.target   │ ├─-.slice   │ └─system.slice   ├─sockets.target   │ ├─cups.socket   │ ├─dbus.socket   │ ├─dm-event.socket   │ ├─iscsid.socket   │ ├─iscsiuio.socket   │ ├─rpcbind.socket   │ ├─systemd-initctl.socket   │ ├─systemd-journald.socket   │ ├─systemd-shutdownd.socket   │ ├─systemd-udevd-control.socket   │ └─systemd-udevd-kernel.socket   ├─sysinit.target   │ ├─dev-hugepages.mount   │ ├─dev-mqueue.mount   │ ├─dmraid-activation.service   │ ├─iscsi.service   │ ├─kmod-static-nodes.service   │ ├─lvm2-lvmetad.socket   │ ├─lvm2-monitor.service   │ ├─plymouth-read-write.service   │ ├─plymouth-start.service   │ ├─proc-sys-fs-binfmt_misc.automount   │ ├─sys-fs-fuse-connections.mount   │ ├─sys-kernel-config.mount   │ ├─sys-kernel-debug.mount   │ ├─systemd-ask-password-console.path   │ ├─systemd-binfmt.service   │ ├─systemd-journal-flush.service   │ ├─systemd-journald.service   │ ├─systemd-modules-load.service   │ ├─systemd-random-seed.service   │ ├─systemd-sysctl.service   │ ├─systemd-tmpfiles-setup-dev.service   │ ├─systemd-tmpfiles-setup.service   │ ├─systemd-udev-trigger.service   │ ├─systemd-udevd.service   │ ├─systemd-update-utmp.service   │ ├─systemd-vconsole-setup.service   │ ├─cryptsetup.target   │ ├─local-fs.target   │ │ ├─-.mount   │ │ ├─boot.mount   │ │ ├─rhel-import-state.service   │ │ ├─rhel-readonly.service   │ │ └─systemd-remount-fs.service   │ └─swap.target   │   ├─dev-disk-by/x2did-dm/x2dname/x2dol/x2dswap.swap   │   ├─dev-disk-by/x2did-dm/x2duuid/x2dLVM/x2dwmmUMFgSImFgksKwxBbGxaioeKcqTyRQ88RtxS76T3TS3XEM247vheZm8SQ77Xgw.swap   │   ├─dev-disk-by/x2duuid-1a736d5d/x2de52a/x2d430c/x2dbe02/x2dff81252749db.swap   │   ├─dev-dm/x2d1.swap   │   ├─dev-mapper-ol/x2dswap.swap   │   ├─dev-mapper-ol/x2dswap.swap   │   └─dev-ol-swap.swap   └─timers.target     └─systemd-tmpfiles-clean.timer  [root@lunar system]#