[20201112]centos 7 rc.local shell script on systemd while booting Linux system.txt

--//centos 7开始全面使用systemd管理启动过程，说真的我自己非常不习惯，也许是老了，接受新生事物有点迟钝。
--//而以前用户要加入一些特殊命令一般都是选择/etc/rc.d/rc.local.但是centos 7开始不会再调用执行。

# ls -l /etc/rc.local /etc/rc.d/rc.local
-rw-r--r--. 1 root root 485 2020-11-12 10:28:16 /etc/rc.d/rc.local
lrwxrwxrwx. 1 root root  13 2020-02-27 01:51:51 /etc/rc.local -> rc.d/rc.local

# systemctl status rc-local.service
* rc-local.service - /etc/rc.d/rc.local Compatibility
   Loaded: loaded (/usr/lib/systemd/system/rc-local.service; static; vendor preset: disabled)
   Active: inactive (dead)

# systemctl enable rc-local.service

# systemctl start rc-local.service

# systemctl status rc-local.service
* rc-local.service - /etc/rc.d/rc.local Compatibility
   Loaded: loaded (/usr/lib/systemd/system/rc-local.service; static; vendor preset: disabled)
   Active: inactive (dead)
Condition: start condition failed at Thu 2020-11-12 10:34:12 CST; 3s ago
           ConditionFileIsExecutable=/etc/rc.d/rc.local was not met
--//不行。

# ls -l /etc/rc.d/rc.local
-rw-r--r--. 1 root root 485 2020-11-12 10:28:16 /etc/rc.d/rc.local
--//没有执行权限。

# chmod 744 /etc/rc.d/rc.local

# systemctl start rc-local.service

# systemctl status rc-local.service
* rc-local.service - /etc/rc.d/rc.local Compatibility
   Loaded: loaded (/usr/lib/systemd/system/rc-local.service; static; vendor preset: disabled)
   Active: active (exited) since Thu 2020-11-12 10:36:05 CST; 1s ago
  Process: 8078 ExecStart=/etc/rc.d/rc.local start (code=exited, status=0/SUCCESS)

Nov 12 10:36:05 localhost.localdomain systemd[1]: Starting /etc/rc.d/rc.local Compatibility...
Nov 12 10:36:05 localhost.localdomain rc.local[8078]: test
Nov 12 10:36:05 localhost.localdomain systemd[1]: Started /etc/rc.d/rc.local Compatibility.

--//ok现在已经执行成功了。