Operating Systems

Oracle Linux 8 User Guide

| Product: Oracle Linux 8

Overview

This guide covers the deployment and configuration of Oracle Enterprise Linux 8 on AWS using cloudimg AMIs from the AWS Marketplace. Oracle Linux 8 is an enterprise grade Linux distribution that provides the reliability and performance needed for production workloads, with full binary compatibility with Red Hat Enterprise Linux 8.

Available versions: Oracle Linux 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, and 8.10. Each version is available as a separate AMI on the AWS Marketplace.

What's included in this AMI:

  • Oracle Enterprise Linux 8 with latest security patches
  • AWS CLI 2.7.7 for AWS service management
  • AWS CloudWatch Agent 1.247352.0b251908 for monitoring and log collection
  • AWS Systems Manager Agent 3.1.1476.0 for remote management
  • Cloud Init 22.1 for instance initialization
  • OS package update script for keeping the system current
  • 24/7 cloudimg support with guaranteed 24 hour response SLA

Prerequisites

Before launching this AMI, ensure you have:

  1. An active AWS account
  2. An active subscription to your chosen Oracle Linux 8 version on AWS Marketplace
  3. An EC2 key pair for SSH access
  4. Familiarity with EC2 instance management and SSH

Recommended Instance Type: t3.small (2 vCPU, 2 GB RAM) or larger. The minimum requirements are 1 vCPU, 1 GB RAM, and 20 GB disk space.

Step 1: Launch the AMI

  1. Navigate to the AWS Marketplace and search for "Oracle Linux 8 cloudimg"
  2. Select the specific minor version you need (8.0 through 8.10)
  3. Click Continue to Subscribe, accept the terms, then Continue to Configuration
  4. Select your preferred Region and Software Version
  5. Click Continue to Launch
  6. Choose Launch through EC2 for full control over instance configuration
  7. Select your instance type (t3.small recommended)
  8. Configure storage: 20 GB gp3 minimum
  9. Configure your Security Group with the following inbound rules:
Port Protocol Source Purpose
22 TCP Your IP SSH access
  1. Select your EC2 key pair and launch the instance

Step 2: Connect via SSH

Once your instance is running and has passed both status checks (2/2), connect using SSH:

ssh -i your-key.pem ec2-user@<public-ip-address>

To switch to the root user:

sudo su -

Step 3: Verify the System

Check the OS version:

cat /etc/oracle-release

Check kernel version:

uname -r

Using AWS CLI

The AWS CLI is preinstalled and ready to use:

aws --version

Ensure your instance has an IAM role with appropriate permissions, or configure credentials with aws configure.

Configuring CloudWatch Agent

Run the configuration wizard as root:

/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-config-wizard

Start the agent:

/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -s -c file:/opt/aws/amazon-cloudwatch-agent/bin/config.json

Check status:

/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -m ec2 -a status

Using Systems Manager

Check SSM Agent status:

systemctl status amazon-ssm-agent

Ensure the instance has an IAM role with AmazonSSMManagedInstanceCore policy.

Configuring Cloud Init

The Cloud Init configuration file is located at:

vi /etc/cloud/cloud.cfg

Server Components

Component Version Install Path
AWS CLI 2.7.7 /usr/local/aws-cli
AWS CloudWatch Agent 1.247352.0b251908 /opt/aws/amazon-cloudwatch-agent
AWS Systems Manager Agent 3.1.1476.0 /usr/bin/amazon-ssm-agent
Cloud Init 22.1 /etc/cloud

Filesystem Layout

Mount Point Size Description
/ 38 GB Root filesystem (NVMe)
/boot 2 GB Operating system kernel files

Note: Oracle Linux 8 uses NVMe storage devices on supported instance types.

Scripts and Log Files

Script/Log Path Description
initial_boot_update.sh /stage/scripts Updates the OS with the latest packages on first boot
initial_boot_update.log /stage/scripts Output log for the boot update script

On Startup

An OS package update script runs on first boot. Disable it with:

rm -f /stage/scripts/initial_boot_update.sh

crontab -e
# Delete the @reboot line, save and exit

Common Administration Tasks

Update all packages:

dnf update -y

Install a package:

dnf install -y package-name

Manage services:

systemctl start service-name
systemctl stop service-name
systemctl enable service-name
systemctl status service-name

View system logs:

journalctl -f

Troubleshooting

Cannot connect via SSH

  1. Verify the instance has passed 2/2 status checks
  2. Check your security group allows port 22 from your IP
  3. Ensure you are using the correct key pair and username (ec2-user)

dnf update fails

  1. Verify internet access (public subnet or NAT gateway)
  2. Check DNS resolution: nslookup yum.oracle.com
  3. Check disk space: df -h

CloudWatch Agent not working

  1. Verify agent status with the amazon-cloudwatch-agent-ctl command
  2. Check IAM role has CloudWatchAgentServerPolicy
  3. Review logs: tail -f /opt/aws/amazon-cloudwatch-agent/logs/amazon-cloudwatch-agent.log

Security Recommendations

  • Restrict SSH access: Only allow port 22 from trusted IP addresses
  • Use IAM roles for AWS API access instead of access keys
  • Keep the system updated: Run dnf update regularly
  • Enable SELinux: Verify with getenforce
  • Configure firewalld for additional host level security
  • Monitor with CloudWatch for CPU, memory, and disk alerts
  • Use SSM Session Manager for secure, auditable remote access

Support

If you encounter any issues with this product, contact cloudimg support:

  • Email: support@cloudimg.co.uk
  • Website: www.cloudimg.co.uk
  • Support hours: 24/7 with guaranteed 24 hour response SLA