Step-by-step tutorial on installing a linux virtual machine

The five pillars of the Linux system are: 1. Kernel, 2. System library, 3. Shell, 4. File system, 5. System tools. The kernel manages hardware resources and provides basic services; the system library provides precompiled functions for applications; the shell is the interface for users to interact with the system; the file system organizes and stores data; and system tools are used for system management and maintenance.

There are three ways to view instance names in Oracle: use the "sqlplus" and "select instance_name from v$instance;" commands on the command line. Use the "show instance_name;" command in SQL*Plus. Check environment variables (ORACLE_SID on Linux) through the operating system's Task Manager, Oracle Enterprise Manager, or through the operating system.

Linux is suitable for servers, development environments, and embedded systems. 1. As a server operating system, Linux is stable and efficient, and is often used to deploy high-concurrency applications. 2. As a development environment, Linux provides efficient command line tools and package management systems to improve development efficiency. 3. In embedded systems, Linux is lightweight and customizable, suitable for environments with limited resources.

To uninstall an Oracle database: stop the Oracle service, remove the Oracle instance, delete the Oracle home directory, clear the registry key (Windows only), and delete the environment variables (Windows only). Please back up the data before uninstalling.

Using Docker on Linux can improve development and deployment efficiency. 1. Install Docker: Use scripts to install Docker on Ubuntu. 2. Verify the installation: Run sudodockerrunhello-world. 3. Basic usage: Create an Nginx container dockerrun-namemy-nginx-p8080:80-dnginx. 4. Advanced usage: Create a custom image, build and run using Dockerfile. 5. Optimization and Best Practices: Follow best practices for writing Dockerfiles using multi-stage builds and DockerCompose.

After Oracle is installed, you can use the following steps: Create a database instance. Connect to the database. Create a user. Create a table. Insert data. Query data. Export data. Import data.

When the Apache 80 port is occupied, the solution is as follows: find out the process that occupies the port and close it. Check the firewall settings to make sure Apache is not blocked. If the above method does not work, please reconfigure Apache to use a different port. Restart the Apache service.

The steps to start Apache are as follows: Install Apache (command: sudo apt-get install apache2 or download it from the official website) Start Apache (Linux: sudo systemctl start apache2; Windows: Right-click the "Apache2.4" service and select "Start") Check whether it has been started (Linux: sudo systemctl status apache2; Windows: Check the status of the "Apache2.4" service in the service manager) Enable boot automatically (optional, Linux: sudo systemctl