How to Update and Upgrade Linux System Safely

Why Regular Updates Matter

• Security: Fix vulnerabilities quickly.
• Stability: Prevent crashes and bugs.
• Features: Get new software and kernel improvements.

Updating on Ubuntu & Debian

# refresh package lists
sudo apt update

# upgrade all packages
sudo apt upgrade -y

# full upgrade (handles dependencies and kernel upgrades)
sudo apt full-upgrade -y

# remove unused packages
sudo apt autoremove -y

Tip: Use apt full-upgrade occasionally to keep your kernel and dependencies aligned.

Updating on CentOS & AlmaLinux

# update all packages
sudo dnf upgrade -y

# clean cache
sudo dnf clean all

# check for kernel updates
sudo dnf list kernel

Tip: After a kernel update, reboot to load the new version:

sudo reboot

Check Current Kernel Version

uname -r

This command shows the active kernel. After a reboot, it should match the latest installed version.

Best Practices

• Update regularly (once a week is recommended).
• Always reboot after kernel or system updates.
• Avoid interrupting updates; it can break packages.
• Back up important data before large upgrades.