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Minor Release Upgrades

Minor release upgrades (e.g., EL 9.3 to 9.4) are the most common maintenance operation. This guide covers the complete dnf update workflow including pre-checks, execution, verification, and rollback.

Checking Available Updates

Section titled “Checking Available Updates”

Before performing an upgrade, review what packages have updates available.

List All Available Updates

Section titled “List All Available Updates”
Check for available updates
dnf check-update

This command returns exit code 100 when updates are available, 0 when there are none, and 1 on error.

View Security Updates Only

Section titled “View Security Updates Only”
List security-related updates only
dnf updateinfo list security

View Update Details

Section titled “View Update Details”
View details for a specific advisory
dnf updateinfo info --advisories=ALSA-2025:1234

View Update Summary

Section titled “View Update Summary”
View update summary statistics
dnf updateinfo summary

Performing the Minor Release Upgrade

Section titled “Performing the Minor Release Upgrade”

Standard Full Update

Section titled “Standard Full Update”
Perform a full system update
dnf update -y

Install Security Updates Only

Section titled “Install Security Updates Only”
Install only security patches
dnf update --security -y

Exclude Specific Packages

Section titled “Exclude Specific Packages”
Update while excluding certain packages
dnf update -y --exclude=kernel* --exclude=php*

Dry Run (No Actual Installation)

Section titled “Dry Run (No Actual Installation)”
Simulate update to check for dependency issues
dnf update --assumeno

Kernel Update Considerations

Section titled “Kernel Update Considerations”

Kernel updates install alongside existing kernels rather than replacing them.

Check the Currently Running Kernel

Section titled “Check the Currently Running Kernel”
View the current kernel version
uname -r

List Installed Kernels

Section titled “List Installed Kernels”
List all installed kernels
rpm -qa kernel-core | sort -V

Update Only the Kernel

Section titled “Update Only the Kernel”
Update only the kernel package
dnf update kernel -y

A reboot is required to use the new kernel after updating.

Using needs-restarting

Section titled “Using needs-restarting”

The needs-restarting tool determines which services or the system itself need a restart after updates.

Install needs-restarting

Section titled “Install needs-restarting”
Install dnf-plugins-core (includes needs-restarting)
dnf install -y dnf-plugins-core

Check If a System Reboot Is Required

Section titled “Check If a System Reboot Is Required”
Check if a full reboot is needed
needs-restarting -r

Exit code 0 means no reboot required; 1 means a reboot is needed.

List Services That Need Restarting

Section titled “List Services That Need Restarting”
List services requiring a restart
needs-restarting -s

Batch Restart Affected Services

Section titled “Batch Restart Affected Services”
Restart all services that need it
needs-restarting -s | xargs -I {} systemctl restart {}

Rollback Strategy

Section titled “Rollback Strategy”

View dnf History

Section titled “View dnf History”
View dnf transaction history
dnf history list

View Details of a Specific Transaction

Section titled “View Details of a Specific Transaction”
View details of a specific transaction
dnf history info <transaction-ID>

Undo a Specific Transaction

Section titled “Undo a Specific Transaction”
Undo a specific update transaction
dnf history undo <transaction-ID> -y

Rollback to a Point in Time

Section titled “Rollback to a Point in Time”
Rollback to state before a given transaction
dnf history rollback <transaction-ID> -y

Kernel Rollback

Section titled “Kernel Rollback”

If a new kernel causes problems, select the old kernel from the GRUB menu at boot time.

Set the default boot kernel to an older version
grubby --set-default /boot/vmlinuz-<old-version>

Scheduling Maintenance Windows

Section titled “Scheduling Maintenance Windows”
Section titled “Recommended Maintenance Workflow”
  1. Notify — Inform relevant teams at least 48 hours in advance
  2. Backup — Create system snapshots or back up critical data
  3. Pre-test — Validate updates in a test environment
  4. Execute — Perform updates within the maintenance window
  5. Verify — Check service status and functionality
  6. Rollback readiness — Confirm that the rollback plan is viable

Create a Pre-Update Snapshot (LVM)

Section titled “Create a Pre-Update Snapshot (LVM)”
Create an LVM snapshot before updating
lvcreate -s -n pre-update-snap -L 10G /dev/vg0/root

Automated Update Script

Section titled “Automated Update Script”
Maintenance window update script example
#!/bin/bash
set -e


echo "=== Maintenance update started: $(date) ==="


# 1. Record current state
rpm -qa --qf '%{NAME}-%{VERSION}-%{RELEASE}.%{ARCH}\n' | sort > /root/pkg-before.txt


# 2. Perform update
dnf update -y


# 3. Record post-update state
rpm -qa --qf '%{NAME}-%{VERSION}-%{RELEASE}.%{ARCH}\n' | sort > /root/pkg-after.txt


# 4. Show changes
echo "=== Package changes ==="
diff /root/pkg-before.txt /root/pkg-after.txt || true


# 5. Check if reboot is needed
if ! needs-restarting -r &>/dev/null; then
    echo "*** System reboot required ***"
fi


echo "=== Maintenance update completed: $(date) ==="

Set Up Automatic Security Updates (Optional)

Section titled “Set Up Automatic Security Updates (Optional)”
Install and enable automatic updates
dnf install -y dnf-automatic


# Configure to only apply security updates
sed -i 's/^upgrade_type.*/upgrade_type = security/' /etc/dnf/automatic.conf
sed -i 's/^apply_updates.*/apply_updates = yes/' /etc/dnf/automatic.conf


systemctl enable --now dnf-automatic.timer

Verify the Automatic Update Timer

Section titled “Verify the Automatic Update Timer”
Check the automatic update timer status
systemctl status dnf-automatic.timer