CentOS is an open source operating system based on Red Hat Enterprise Linux, suitable for server environments. 1. Select the appropriate media and options during installation and configure network, firewall and user permissions. 2. Use useradd, usermod and systemctl commands to manage users and services, and update software packages regularly. 3. Basic operations include using yum installation software and systemctl management services, and advanced features such as SELinux to enhance security. 4. Check the system log to solve common errors. Optimizing performance requires monitoring resources and cleaning of unnecessary files.

introduction

In today's IT world, CentOS, as a stable Linux distribution, has become the preferred tool for many system administrators. Whether you are a beginner or an experienced veteran, mastering the skills of using CentOS will greatly improve your work efficiency. This article will take you into the depth of all aspects of CentOS, from basic installation to advanced management skills, and help you become an excellent CentOS system administrator.

Review of basic knowledge

CentOS, full name is Community ENTerprise Operating System, is an open source operating system based on Red Hat Enterprise Linux (RHEL) source code. It is known for its stability and security and is ideal for use in server environments. As a system administrator, you need to be familiar with the basic command line operations of Linux, such as file management, user management, network configuration, etc., which are the basics of working on CentOS.

In CentOS, the commonly used package management tool is Yum (Yellowdog Updater, Modified), which can help you easily install, update and delete packages. In addition, CentOS also supports Systemd, a system and service manager that can be used to control system startup and management services.

Core concept or function analysis

Installation and configuration of CentOS

Installing CentOS is a relatively simple process, but to ensure the security and performance of the system, you need to make some critical configurations during the installation process. First, you need to select the right installation media, usually through a DVD or USB drive. During the installation process, you can choose different installation options, such as minimizing installation, desktop environment installation, etc., and choose according to your needs.

 # Commonly used commands during installation sudo yum install -y epel-release
sudo yum update -y

After the installation is completed, you need to configure network settings, firewall rules, user permissions, etc. These are key steps to ensure the safe and efficient operation of the system.

System management and maintenance

CentOS system management involves many aspects, including user management, file system management, service management, etc. Users can be added and modified easily using useradd and usermod commands, while systemctl commands can be used to manage system services.

 # Add new user sudo useradd -m newuser

# Change user password sudo passwd newuser

# Start and stop the service sudo systemctl start httpd
sudo systemctl stop httpd

It is important to regularly update packages and system patches when maintaining CentOS systems, which can help you fix known security vulnerabilities and improve system performance.

Example of usage

Basic usage

It is very intuitive to perform basic system management operations on CentOS. For example, you can use the yum command to install the package:

 # Install Apache web server sudo yum install -y httpd

You can also use the systemctl command to manage services:

 # Start the Apache service sudo systemctl start httpd

# Enable Apache service to automatically start sudo systemctl when the system starts.

Advanced Usage

For experienced system administrators, CentOS provides many advanced features, such as using SELinux (Security-Enhanced Linux) to enhance system security. SELinux can help you define finer-grained access control policies to protect your system from unauthorized access.

 # Check SELinux status sestatus

# Temporarily disable SELinux
setenforce 0

# Permanently disable SELinux, you need to edit the configuration file sudo vim /etc/selinux/config

Common Errors and Debugging Tips

When using CentOS, you may encounter some common errors, such as network configuration errors, software package dependency problems, etc. An effective way to solve these problems is to view system log files, such as /var/log/messages and /var/log/secure , which record the system's running status and error information.

 # View system log sudo tail -f /var/log/messages

# View security log sudo tail -f /var/log/secure

Performance optimization and best practices

In practical applications, it is very important to optimize the performance of CentOS system. You can use top and htop commands to monitor system resource usage to identify potential performance bottlenecks.

 # Monitor system resource usage top
htop

In addition, regular cleaning of unnecessary packages and files is also a good way to optimize system performance:

 # Clean up unnecessary software packages sudo yum autoremove

# Clean the cache sudo yum clean all

As a system administrator, it is also very important to develop good programming habits and best practices. For example, writing highly readable scripts and using version control systems to manage configuration files can help you manage CentOS systems more efficiently.

In short, CentOS is a powerful and stable Linux distribution. Mastering its usage skills will greatly improve your system management capabilities. I hope this article can provide you with valuable guidance and help.

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