Common Issues for Beginners: Methods to Update Linux Systems

### Why Update the Linux System? Updates fix security vulnerabilities, add new features (e.g., support for new hardware), optimize performance, and enhance system security and usability. ### Pre-Update Preparation 1. **Backup Data**: Back up important files in advance (e.g., via USB copy). 2. **Identify the Distribution**: - For Ubuntu/Debian-based systems: Use `lsb_release -a` or `cat /etc/os-release`. - For CentOS/RHEL-based systems: Use `cat /etc/redhat-release`. ### General Update Steps (Mainstream Distributions) - **Ubuntu/Debian-based**: - `sudo apt update` (Update package lists) → - `sudo apt upgrade` (Upgrade software); use `full-upgrade` for complex dependencies. - **CentOS/RHEL-based**: `sudo dnf update` (yum is also supported, but dnf is recommended). ### Common Issues and Solutions - **Insufficient Permissions**: Add `sudo` before commands. - **Download Failures**: Switch to a domestic mirror source (e.g., Alibaba Cloud) or check the network. - **Black Screen After Update**: Restart; if ineffective, boot into recovery mode for repair. - **Rollback**: Ubuntu