Linux Update Best Practices: Focusing on Ubuntu and Oracle Linux

It’s essential to maintain and your Linux systems for dependability, performance, and security. The hazards, factors to be aware of, kernel updates, rollback methods (including those without backups), and the most recent developments in kernel live patching will all be covered in this blog article on best practices for Linux update and focusing on updating Ubuntu and Oracle Linux.

Introduction to Linux Updates

Linux updates are essential for maintaining system security, stability, and performance. Both Ubuntu and Oracle Linux provide regular updates that address security vulnerabilities, fix bugs, and introduce new features. However, managing these updates requires careful planning and execution to avoid potential issues.

Importance of Regular Linux Updates

Regular Linux updates are essential for several reasons:

1. Security: Updates often include patches for vulnerabilities that could be exploited by attackers.
2. Stability: Bug fixes improve system stability and performance.
3. Compatibility: Ensures compatibility with new software and hardware.

Neglecting Linux updates can leave systems vulnerable to attacks and result in compatibility issues with newer applications.

Risks and Considerations for Linux Updates

Updating Linux systems, while necessary, comes with certain risks:

1. Compatibility Issues: New updates might not be compatible with existing software or configurations.
2. Downtime: Updates may require system reboots, leading to downtime.
3. System Failures: Improper updates or incompatible changes can cause system failures.

To mitigate these risks, consider the following:

• Backups: Always back up your system before performing updates.
• Testing: Test updates on a staging environment before applying them to production systems.
• Change Management: Implement a change management process to plan, test, and review updates.

Kernel Update Considerations

The kernel is the core of the Linux operating system, and updating it requires special attention:

1. Version Compatibility: Ensure the new kernel version is compatible with your hardware and software.
2. Dependencies: Verify that all kernel modules and drivers are available for the new version.
3. Performance: Newer kernels may offer performance improvements or new features.

Kernel Live Patching

Kernel live patching is a method to apply patches to the running kernel without rebooting the system. This is crucial for minimizing downtime in production environments. Tools like Canonical’s Livepatch for Ubuntu and Oracle Ksplice for Oracle Linux provide this functionality.

Benefits of Kernel Live Patching:

• Minimized Downtime: Apply critical patches without rebooting.
• Increased Security: Quickly address security vulnerabilities.
• Improved Stability: Avoid the risks associated with full system reboots.

Best Practices for Kernel Updates

1. Use Live Patching: Where possible, use live patching to apply critical updates without downtime.
2. Keep Multiple Kernel Versions: Retain multiple kernel versions to fall back on in case of issues. Generally, keep at least two to three versions.
3. Regularly Monitor: Continuously monitor kernel updates and their impacts.

Full System Rollback Procedures

Even with careful planning, updates can sometimes go wrong. Having a rollback plan is crucial:

1. Full System Rollback:
   • Snapshots: Use filesystem snapshots (e.g., LVM, Btrfs) to revert the entire system to a previous state.
   • Backup Restores: Restore from a full system backup if snapshots are not available.
2. Kernel Rollback:
   • Grub Configuration: Edit the Grub bootloader configuration to boot from a previous kernel version.
   • Remove Faulty Kernel: Uninstall the problematic kernel version.

Rollback Procedures Without Backups

If you haven’t created backups or snapshots, you can still perform rollbacks, similar to how you might remove problematic Windows updates. Here’s how:

Rollback Specific Packages on Ubuntu

1. Identify the Installed Version: dpkg –list | grep
2. Find Available Versions: apt-cache showpkg
3. Install an Older Version: sudo apt install <package_name>=<version>
4. Prevent Automatic Updates: sudo apt-mark hold <package_name>

Rollback Specific Packages on Oracle Linux

1. Identify the Installed Version: rpm -qa | grep <package_name>
2. Find Available Versions: yum –showduplicates list <package_name>
3. Install an Older Version: sudo yum install <package_name>-<version>
4. Prevent Automatic Updates: sudo yum versionlock <package_name>-<version>

Rollback for Kernel Updates Without Backups

Ubuntu

1. List Installed Kernels: dpkg –list | grep linux-image
2. Remove Faulty Kernel: sudo apt remove –purge linux-image-<faulty_version>
3. Update Grub: sudo update-grub
4. Reboot: sudo reboot

Oracle Linux

1. List Installed Kernels: rpm -qa | grep kernel
2. Remove Faulty Kernel: sudo yum remove kernel-<faulty_version>
3. Update Grub: sudo grub2-mkconfig -o /boot/grub2/grub.cfg
4. Reboot: sudo reboot

Update Procedures for Ubuntu

1. Update Package Lists: sudo apt update
2. Upgrade Packages: sudo apt upgrade
3. Full Distribution Upgrade: sudo apt dist-upgrade
4. Kernel Update:
   • Install Specific Kernel: sudo apt install linux-image-<version>
   • Reboot: sudo reboot

Update Procedures for Oracle Linux

1. Update Package Lists: sudo yum check-update
2. Upgrade Packages: sudo yum update
3. Kernel Update:
   • Install Specific Kernel: sudo yum install kernel-<version>
   • Reboot: sudo reboot

Conclusion

Keeping Linux update is crucial for security and performance. By understanding the risks, planning updates carefully, using live patching, and having robust rollback procedures (even without backups), you can maintain stable and secure systems. Regular updates, combined with these best practices, will help ensure your Linux environments run smoothly and securely.

References

1. Ubuntu System Updates and Upgrades
   • Ubuntu Official Documentation: Managing Packages
   • Ubuntu Official Documentation: Security Updates
   • This page explains how to update and upgrade software packages on Ubuntu, including critical security updates.
2. Oracle Linux: Managing Software and Updates
   • Oracle Linux: Yum and DNF Package Management
   • Oracle Linux Release Notes
   • Detailed guides on managing software packages and updates in Oracle Linux, including the dnf and yum package managers.
3. Kernel Live Patching
   • Canonical Livepatch Service
   • Oracle Ksplice: Zero Downtime Kernel Updates
   • These pages cover Canonical’s Livepatch service for Ubuntu and Oracle’s Ksplice for live kernel patching with zero downtime.
4. Kernel Rollback and Update Management
   • Ubuntu Kernel Management
   • KernelCare for Live Patching
   • These resources provide insights into kernel management and rollback options for Ubuntu and kernel live patching for various distributions.
5. Handling Updates and Rollbacks in Linux
   • Rolling Back an Update in Ubuntu: Snapshots and System Backups
   • Using Oracle Linux Btrfs Snapshots for Rollbacks
   • Guides on how to perform system rollbacks in Ubuntu and Oracle Linux using snapshots and backup methods.
6. Best Practices for Linux System Maintenance
   • Red Hat: Best Practices for Maintaining Linux Systems
   • Oracle Linux: System Administration Guide
   • Best practices for maintaining Linux systems, including patch management and regular updates.
7. Linux Kernel Updates: How to Handle Them Safely
   • How to Update the Linux Kernel Safely
   • Linux Kernel Archives
   • Information on updating and maintaining the Linux kernel, including best practices for ensuring safe updates.
8. Systemd and GRUB for Rollback and Recovery
   • Systemd Bootloader and GRUB
   • Ubuntu GRUB Recovery and Kernel Options
   • These resources explain how to use systemd, GRUB, and other bootloader tools for rollback and recovery.
9. Best Practices for Managing Multiple Kernels
   • Keep Multiple Kernels in Ubuntu
   • Managing Kernel Versions in Oracle Linux
   • Guidelines on how to manage and retain multiple kernel versions in Ubuntu and Oracle Linux.

External Tools and Services

1. Timeshift: System Backup and Restore Utility
   • Timeshift GitHub Repository
   • Timeshift is an open-source tool for creating system snapshots and restoring previous versions of a Linux system.
2. Snapper: Btrfs Snapshot Management Tool
   • Snapper Documentation
   • Snapper is a tool used for managing Btrfs snapshots on Linux, which is particularly useful for rollback scenarios.
3. Canonical Ubuntu Advantage for Enterprises
   • Ubuntu Advantage
   • Ubuntu Advantage offers comprehensive security and management services, including livepatches for kernel updates.
4. Oracle Unbreakable Enterprise Kernel (UEK)
   • Oracle UEK Documentation
   • Oracle’s UEK provides optimized kernel updates and live patching solutions for Oracle Linux systems.

Further Reading

Oracle Linux Automation Manager: Supercharge Your IT with Intelligent Automation

Demystifying JBD2: The Guardian Angel of Ext4 Filesystems

Linux Troubleshooting: Mastering the Powerful Tools for Fixing and Optimizing Your System

Canonical Kubernetes vs. Native: Unmasking the Cloud Champions