table of Contents

Shutdown command

Centos system optimization

1. Learn to turn off the firewall

2. Turn off the selinu service

3. Install vmtools

Ubuntu16 installation

CentOS6.9 installation steps

Turn on the virtual machine

Installation interface introduction
1. Install or upgrade an existing operating system
2. Install the basic graphics card driver for the operating system
3. Enter the rescue mode
4. Boot into the system from the local disk
5. Memory detection

Always forward:

Finish

centos turn off screen saver

Centos always blacks out when it is not applicable for a period of time, what should I do?

How to call Chinese input method

Right-click on the desktop to open the terminal:

Terminal to adjust the font size:

Select input method

Open advanced

The shortcut key is ctrl+space

Shutdown command

init 0 (used a lot) / poweroff / shutdown

Centos system optimization

1. Learn to turn off the firewall

iptables -nL View firewall status (view all rules of the current table, the filter table is viewed by default)

Turn off the firewall:
enter setup under the command line and a graphical interface appears

Press tab to select OK

Centos7 view firewall status: firewall-cmd --state
centos7 close the firewall command: systemctl stop firewalld.service
permanently close the firewall: chkconfig -level 35 iptables off

Centos6 view firewall status: service iptables status or /etc/init.d/iptables status
Centos6 to turn on/off/restart the firewall: service iptables start/stop/restart to
permanently turn off the firewall: /sbin/service iptables stop chkconfig iptables off to take effect after restarting the system

Use root authority to turn off the firewall: execute /etc/init.d/iptables stop, and run the command /etc/init.d/iptables status to view the firewall status. This method is to temporarily disable the firewall. After restarting the system, the firewall will automatically start

You can also use setup to turn off the firewall in centos7

Press space to close

2. Turn off the selinu service

The selinux service is also a function that restricts operating system files from being read and files being shared

Now, all the files of my operating system are equivalent to supermarket products, such as web service port 80, I will definitely share the homepage, all the products are labeled, if you want to see the content inside, it is equivalent If you want to buy it, selinux is a bit like a security agency in a supermarket. Selinux has two functions: one is alarm and the other is interception.

Remove the alarm from the supermarket and remove the security guards. In a free environment, how to turn it off?

1. Need to modify the file /etc/selinux/config

Introduce a graphical editor gedit, which is convenient for novices: input the command gedit on the screen and it will pop up

[root@Waffle ~]# gedit /etc/selinux/config

The configuration file is loaded into the memory after the system is started, and it is now effective in the memory. If you change the file, the memory is not recognized or not recognized. Restart
getenforce (check the current selinux status)