Linux Updates: Command Line Guide

For Fedora and Arch Linux users, there are equivalent tools and methods to achieve automatic updates, similar to unattended-upgrades on Debian-based systems.

Red Hat/Fedora: Using DNF Automatic

Fedora uses dnf as its package manager, and DNF Automatic handles unattended updates.

1. Install DNF Automatic:

   sudo dnf install dnf-automatic
   

2. Configure DNF Automatic:
   Edit the configuration file at /etc/dnf/automatic.conf:
   – Enable automatic updates by setting:

   [commands]
   upgrade_type = default
   apply_updates = yes
   

   – Optionally, configure email notifications in the [emitters] section.

3. Enable the Service:
   Start the systemd service to schedule updates automatically:

   sudo systemctl enable --now dnf-automatic.timer
   

This setup ensures that your Fedora system checks for updates and applies them regularly.

Arch Linux: Using Pacman with a Systemd Timer

Arch Linux does not have a direct equivalent like unattended-upgrades, but you can automate updates with a custom systemd service and timer.

1. Create an Update Script:

   sudo nano /usr/local/bin/auto-pacman-update.sh
   

   Add the following lines:

   #!/bin/bash
   sudo pacman -Syu --noconfirm
   

   Make the script executable:

   sudo chmod +x /usr/local/bin/auto-pacman-update.sh
   

2. Create a Systemd Service:

   sudo nano /etc/systemd/system/auto-pacman-update.service
   

   Configure the service:

   [Unit]
   Description=Automatic Pacman Updates
   
   [Service]
   Type=oneshot
   ExecStart=/usr/local/bin/auto-pacman-update.sh
   

3. Create a Systemd Timer:

   sudo nano /etc/systemd/system/auto-pacman-update.timer
   

   Set it to run daily:

   [Unit]
   Description=Run automatic Pacman updates daily
   
   [Timer]
   OnCalendar=daily
   Persistent=true
   
   [Install]
   WantedBy=timers.target
   

4. Enable the Timer:

   sudo systemctl enable --now auto-pacman-update.timer
   

This setup will keep your Arch Linux system updated daily without manual input.

Even with regular updates, problems can occur. Here are solutions to common issues across Debian/Ubuntu, Red Hat/Fedora, and Arch Linux systems:

1. Broken Package Error

– Debian/Ubuntu:

sudo apt --fix-broken install

Or:

sudo dpkg --configure -a

– Red Hat/Fedora:

sudo dnf check
sudo dnf clean all
sudo dnf upgrade --refresh

These commands will check for broken packages, clean the cache, and attempt to fix any issues during the upgrade.

– Arch Linux:

sudo pacman -Syu --overwrite '*'

If the error persists, use:

sudo pacman -Syyu

This forces a database refresh and attempts to resolve any broken packages.

2. GPG Key Error

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <KEYID>

sudo apt-key adv --keyserver keyring.debian.org --recv-keys <KEYID>

– Red Hat/Fedora:

sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-<version>

Or manually add the key from the package source:

sudo dnf install fedora-gpg-keys

– Arch Linux:

sudo pacman-key --init
sudo pacman-key --populate archlinux
sudo pacman -Syu

This reinitializes and populates the keyring, then updates the system.

3. Update Process Hangs or Fails

– Debian/Ubuntu:

sudo killall apt-get
sudo rm /var/lib/apt/lists/lock
sudo rm /var/cache/apt/archives/lock
sudo apt update

– Red Hat/Fedora:

sudo rm -f /var/run/dnf.lock
sudo dnf clean all
sudo dnf makecache

– Arch Linux:

sudo rm -f /var/lib/pacman/db.lck
sudo pacman -Syu

This removes the lock file and allows you to retry the update process.

Keeping your Linux kernel updated is vital for system security and performance across all distributions.

Checking the Current Kernel Version

Use the following command on any Linux distribution to check your current kernel version:

uname -r

Installing New Kernel Versions

Updating the kernel manually is straightforward and varies slightly by distribution:

– Debian/Ubuntu:

sudo apt install linux-generic

This installs the latest generic kernel available in the repository.

– Red Hat/Fedora:

sudo dnf upgrade kernel

For Fedora, this updates the kernel to the latest version in the system’s repository.

– Arch Linux:

sudo pacman -S linux

This command installs the latest stable kernel available in the Arch repository.

For Ubuntu users, advanced kernel management can be done using tools like Mainline, which allows selecting specific kernels beyond what’s available in the default repository:

For Debian, it’s recommended to avoid using PPAs, as they can introduce instability. Instead, use the default repositories and the linux-image-amd64 metapackage for kernel updates:

sudo apt install linux-image-amd64

This approach provides a stable way to update the kernel without relying on external sources.

– Red Hat/Fedora:
Use the ELRepo repository for custom kernels:

sudo dnf install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm
sudo dnf --enablerepo=elrepo-kernel install kernel-ml

This installs the latest mainline kernel from the ELRepo repository.

– Arch Linux:
Install a specific kernel using the AUR or a custom package:

sudo pacman -S linux-lts

This installs the Long-Term Support (LTS) kernel, providing a stable alternative.

Also read: Quick Tips for a more stable Arch Linux experience

Tip: Always test new kernel versions in a staging environment before deploying them to production systems to avoid potential issues.

Downgrading to a Previous Kernel

If a new kernel causes stability problems, you can revert to an older kernel:

• Debian/Ubuntu:
  Reboot and hold the Shift key during startup to access the GRUB menu, then select a previous kernel version.
• Red Hat/Fedora:
  Reboot and press Esc during startup to enter the GRUB menu, then choose an older kernel version from the list.
• Arch Linux:
  Reboot and press Esc or Shift to access the GRUB menu, allowing you to select a different kernel.

This method lets you resolve stability issues without performing a full rollback of your system.

Graphical Tools for Managing Linux Updates

While command-line tools offer control and flexibility, graphical update managers simplify the process:

– Ubuntu Software Updater: Launch from the application menu to check for updates automatically and install them easily.

– Fedora PackageKit: Provides a visual interface for handling updates and dependencies, reducing the need for command-line input.

– Arch Linux Pamac: Offers a GUI for managing updates and packages, making it user-friendly for those preferring a graphical approach.

These tools are ideal for users who prefer a GUI experience.

Reviewing Linux Update Logs

Monitoring update logs helps track changes and diagnose issues after updates:

– Debian/Ubuntu:

less /var/log/apt/history.log

– Red Hat/Fedora:

less /var/log/dnf.rpm.log

– Arch Linux:

less /var/log/pacman.log

Regularly reviewing these logs ensures you stay informed about system changes and helps troubleshoot problems effectively.

Backup Before Major Linux Updates

Creating backups before major updates is essential to protect your data. Focus on backing up important directories like /home and /etc:

1. Use rsync for efficient backups:

   rsync -av --progress /home /backup/location/
   

2. Store backups in a separate, secure location to simplify recovery if needed. I use Rclone to sync to Google Drive on Kali + i3 on my laptop (free) and OverGrive on my Kali + Gnome desktop (paid).

Backing up your system before updates is a smart precaution that can save time and prevent data loss.