Are you new to Linux and find system updates and upgrades a bit intimidating? Actually, it’s as simple as patching your phone or installing new features, and it’s crucial! Today, I’ll guide you through the process step by step in the simplest way possible, so your system stays secure and powerful.
一、Why Update and Upgrade Your System?¶
In short, system updates fix vulnerabilities and security patches to make your system safer. System upgrades improve software versions, add new features, or enhance performance. These two steps are key to keeping your Linux system running smoothly. For new users, it’s essential to develop the habit of checking and updating regularly.
For example: If a critical vulnerability isn’t patched, it’s like leaving your door unlocked—hackers could exploit it to access your data. Upgrading software, like updating Python to the latest version, can make programs run faster and offer new features.
二、Essential Steps for Beginners (Ubuntu/Debian & CentOS/RHEL)¶
Different Linux distributions (e.g., Ubuntu, CentOS, Fedora) use slightly different commands, but the core logic is the same. Below are examples for Ubuntu/Debian and CentOS/RHEL.
Step 1: Verify System Information (Optional but Recommended)¶
Open the terminal (shortcut: Ctrl+Alt+T). First, check your system details:
- Check kernel version: uname -a (e.g., 5.15.0-xx-generic)
- Check distribution info: lsb_release -a (Ubuntu shows Ubuntu 20.04 LTS, CentOS shows CentOS Linux release 8.5.2111)
Step 2: Update Package Lists (Critical!)¶
Think of package lists as “weekly sale flyers”—updating them ensures you know which software has new versions.
- Ubuntu/Debian: Run sudo apt update (sudo temporarily grants admin privileges; enter your password when prompted).
- CentOS/RHEL: Run sudo dnf check-update or sudo yum check-update.
Step 3: Perform System Upgrade¶
After updating the list, upgrade the packages. Always update the list first, then upgrade!
- Ubuntu/Debian: sudo apt upgrade (lists all updatable packages; type y to confirm).
- CentOS/RHEL: sudo dnf upgrade or sudo yum upgrade.
Step 4: Resolve Dependencies and Conflicts (Common Issue)¶
Updates may encounter “dependency conflicts” (e.g., two software needing different versions of the same library). The system will prompt you to keep the old version or install the new one.
- For new users: Simply type y (confirm) or n (don’t keep) as prompted. y is usually safer.
- If asked about “preserving configuration files”, choose N to overwrite old configs (recommended for new users to avoid conflicts).
Step 5: Reboot the System (Mandatory!)¶
If the kernel (Linux kernel), core components, or critical services are updated, reboot is required for changes to take effect!
Run: sudo reboot
After reboot, the system will apply the updates.
三、Beginner Pitfalls: Key Reminders¶
- Backup Data: Always back up important files (e.g., documents, configs) before updating to prevent issues.
- Distinguish Package Managers: Ubuntu uses
apt, CentOS usesyum/dnf. Never runapt upgradeon CentOS—it will cause errors! - Avoid Updating During Critical Services: If running services like web servers or databases, pause them first.
- Stable Network: Don’t interrupt the update (e.g., avoid using mobile hotspots for large updates).
- “Package Not Found” Error?
Check if software sources are working:
- Ubuntu: Edit/etc/apt/sources.listto confirm repo URLs.
- CentOS: Runsudo dnf clean allto clear cache.
四、Post-Update Checks and Cleanup¶
- Verify Updates: After reboot, run
uname -a(check kernel version) orlsb_release -a(check distribution version). - Clean Up Cache:
- Ubuntu:
sudo apt clean - CentOS:
sudo dnf clean all
This frees up disk space.
Summary¶
Updating and upgrading Linux is simpler than it seems—just master the basic commands and steps. Remember: regular updates, backups, and avoiding command mix-ups will keep your system “healthy.” It may feel overwhelming at first, but with practice, you’ll get the hang of it. If you encounter issues, check error messages or ask the community—this is all part of learning! Enjoy exploring Linux!