Installing Rocky Linux 9: Complete Installation Guide

Introduction

Rocky Linux 9 stands as a premier enterprise Linux distribution, born from the CentOS community’s need for a stable, production-ready alternative. Designed as a 100% bug-for-bug compatible downstream build of Red Hat Enterprise Linux (RHEL), Rocky Linux delivers enterprise-grade stability while maintaining the open-source principles that made CentOS successful. This comprehensive guide walks through every aspect of installing Rocky Linux 9, from initial planning to post-installation optimization.

Understanding Rocky Linux

The Rocky Linux Story

Rocky Linux emerged in 2020 following Red Hat’s announcement to shift CentOS from a stable release to a rolling preview. Founded by Gregory Kurtzer (original co-founder of CentOS), Rocky Linux aims to provide a community-driven, enterprise-ready operating system that organizations can rely on for mission-critical workloads.

Key Features

100% RHEL Compatible: Binary compatible with RHEL 9
Community Driven: Governed by the Rocky Enterprise Software Foundation
Long-term Support: 10-year lifecycle matching RHEL
Free and Open Source: No licensing fees or subscriptions
Enterprise Ready: Suitable for production workloads

Pre-Installation Planning

Hardware Requirements

Minimum Specifications

CPU: 1.5 GHz 64-bit processor (x86_64 or ARM64)
RAM: 2 GB (1.5 GB for text mode)
Storage: 20 GB available disk space
Network: Ethernet or wireless adapter
Display: VGA resolution (1024x768)

Recommended Specifications

CPU: Multi-core 64-bit processor with virtualization extensions
RAM: 8 GB or more
Storage: 50 GB SSD/NVMe
Network: Gigabit Ethernet
Display: 1920x1080 or higher

Production Environment Specifications

CPU: Dual socket, 8+ cores per socket
RAM: 32 GB minimum, 64 GB+ recommended
Storage: Hardware RAID with SSD/NVMe
Network: Redundant Gigabit/10 Gigabit
Power: Redundant power supplies

Compatibility Checklist

Before installation, verify:

Hardware compatibility (check Rocky Linux HCL)
RAID controller support
Network adapter drivers
GPU compatibility (if applicable)
Virtualization platform support

Obtaining Rocky Linux 9

Download Options

1. DVD ISO (Full Installation)

# Download full DVD ISO (9+ GB)
wget https://download.rockylinux.org/pub/rocky/9/isos/x86_64/Rocky-9-latest-x86_64-dvd.iso

# Alternative mirror
curl -O https://mirror.rockylinux.org/pub/rocky/9/isos/x86_64/Rocky-9-latest-x86_64-dvd.iso

2. Minimal ISO (Network Installation)

# Download minimal ISO (~2 GB)
wget https://download.rockylinux.org/pub/rocky/9/isos/x86_64/Rocky-9-latest-x86_64-minimal.iso

3. Boot ISO (Netinstall)

# Download boot ISO (~800 MB)
wget https://download.rockylinux.org/pub/rocky/9/isos/x86_64/Rocky-9-latest-x86_64-boot.iso

Verifying Downloads

Checksum Verification

# Download checksum file
wget https://download.rockylinux.org/pub/rocky/9/isos/x86_64/CHECKSUM

# Verify SHA256
sha256sum -c CHECKSUM 2>&1 | grep OK

# Verify specific ISO
sha256sum Rocky-9-latest-x86_64-dvd.iso

GPG Signature Verification

# Import Rocky Linux GPG key
curl -O https://download.rockylinux.org/pub/rocky/RPM-GPG-KEY-Rocky-9

# Import the key
gpg --import RPM-GPG-KEY-Rocky-9

# Verify signature
gpg --verify Rocky-9-latest-x86_64-dvd.iso.sig Rocky-9-latest-x86_64-dvd.iso

Creating Installation Media

Linux Methods

Using dd Command

# List block devices
lsblk
sudo fdisk -l

# Write ISO to USB (replace sdX with your device)
sudo dd if=Rocky-9-latest-x86_64-dvd.iso of=/dev/sdX bs=4M status=progress conv=fsync

# Alternative with progress
sudo dd if=Rocky-9-latest-x86_64-dvd.iso of=/dev/sdX bs=4M status=progress oflag=direct

Using Ventoy (Recommended)

# Install Ventoy
wget https://github.com/ventoy/Ventoy/releases/download/v1.0.96/ventoy-1.0.96-linux.tar.gz
tar -xzf ventoy-1.0.96-linux.tar.gz
cd ventoy-1.0.96

# Install to USB
sudo ./Ventoy2Disk.sh -i /dev/sdX

# Copy ISO to USB
cp Rocky-9-latest-x86_64-dvd.iso /media/USB/

Windows Methods

Using Rufus

Download Rufus from https://rufus.ie
Insert USB drive (8GB minimum)
Select Rocky Linux ISO
Choose “GPT” for UEFI or “MBR” for BIOS
Select “DD Image” mode
Click “START”

Using balenaEtcher

Download from https://etcher.io
Select Rocky Linux ISO
Select target USB drive
Click “Flash!”

BIOS/UEFI Configuration

Pre-boot Settings

UEFI Systems

1. Enter UEFI (F2/F10/F12/DEL during boot)
2. Disable Secure Boot (may be required)
3. Enable UEFI boot mode
4. Set USB/DVD as first boot device
5. Enable virtualization (Intel VT-x/AMD-V)
6. Save and exit

Legacy BIOS Systems

1. Enter BIOS setup
2. Set boot order (USB/DVD first)
3. Enable virtualization extensions
4. Disable fast boot
5. Save and exit

Installation Walkthrough

Boot Process

Insert installation media and power on
Select boot option:
- Install Rocky Linux 9 - Standard installation
- Test this media & install Rocky Linux 9 - Verify media integrity
- Troubleshooting - Advanced options

Anaconda Installer

Welcome Screen

Select installation language
Choose keyboard layout
Click “Continue”

Installation Summary Hub

The installation summary presents all configuration options:

1. Localization

Language Support:

Primary: English (United States)
Additional: Add languages as needed

Time & Date:

Select timezone
Configure NTP servers:

0.rocky.pool.ntp.org
1.rocky.pool.ntp.org
2.rocky.pool.ntp.org
3.rocky.pool.ntp.org

2. Software

Software Selection:

Base Environments:

Minimal Install: Core system only (~600 packages)
Server: Basic server platform (~1500 packages)
Server with GUI: GNOME desktop environment
Workstation: Development workstation
Custom Operating System: Minimal base
Virtualization Host: KVM platform

Add-ons by Environment:

For Server:

□ Container Management
□ Development Tools
□ .NET Runtime
□ Graphical Administration Tools
□ Headless Management
□ Legacy UNIX Compatibility
□ Network Servers
□ RPM Development Tools
□ Scientific Support
□ Security Tools
□ Smart Card Support
□ System Tools

3. System

Installation Destination:

Automatic Partitioning

Let installer create partitions automatically:

Uses LVM by default
Creates standard layout
Suitable for most use cases

Manual Partitioning (Advanced)

Standard Partition Layout:

# UEFI Systems
/boot/efi    512 MB    EFI System Partition    FAT32
/boot        1 GB      Boot Partition          XFS
/            50 GB     Root Partition          XFS
/home        Variable  Home Partition          XFS
swap         RAM size  Swap Partition          Swap

# BIOS Systems
/boot        1 GB      Boot Partition          XFS
/            50 GB     Root Partition          XFS
/home        Variable  Home Partition          XFS
swap         RAM size  Swap Partition          Swap

LVM Layout (Recommended):

# Physical Layout
/boot/efi    512 MB    Standard Partition      FAT32 (UEFI only)
/boot        1 GB      Standard Partition      XFS
PV           Remaining  Physical Volume         LVM

# Volume Group: rl
Logical Volumes:
rl-root      50 GB     /                       XFS
rl-home      Variable  /home                   XFS
rl-var       20 GB     /var                    XFS
rl-var-log   10 GB     /var/log                XFS
rl-tmp       10 GB     /tmp                    XFS
rl-swap      RAM size  swap                    Swap

Advanced Partitioning Options:

Encryption:

# Full disk encryption (except /boot)
[x] Encrypt my data
Passphrase: [strong passphrase]

RAID Configuration:

# Software RAID setup
RAID Level: RAID 1 (Mirror) or RAID 10
Members: Select physical disks

4. Network & Host Name

Network Configuration:

Ethernet Configuration:

# DHCP (Automatic)
[x] Connect automatically
Method: Automatic (DHCP)

# Static IP
Method: Manual
Address: 192.168.1.100
Netmask: 255.255.255.0
Gateway: 192.168.1.1
DNS: 8.8.8.8, 8.8.4.4
Search domains: example.com

Hostname:

# Set FQDN
rocky9.example.com

User Settings

Root Password

Set a strong root password:

Minimum 12 characters
Mix of upper/lowercase, numbers, symbols
Avoid dictionary words

User Creation

Full name: System Administrator
Username: admin
[x] Make this user administrator
[x] Require password to use this account
Password: [strong password]

Begin Installation

Review all settings
Click “Begin Installation”
Monitor progress (~20-40 minutes)
Reboot when complete

Post-Installation Configuration

Initial System Setup

# Login as root or admin user
# Update system immediately
sudo dnf update -y

# Install essential packages
sudo dnf install -y \
    vim-enhanced \
    bash-completion \
    wget \
    curl \
    git \
    htop \
    net-tools \
    bind-utils \
    yum-utils

Network Configuration

Verify Network Settings

# Check interfaces
ip addr show
nmcli device status

# Test connectivity
ping -c 4 8.8.8.8
ping -c 4 google.com

# Check routing
ip route show

Configure Additional Interfaces

# Add static IP to second interface
nmcli con add type ethernet \
    con-name eth1 \
    ifname eth1 \
    ip4 192.168.2.100/24 \
    gw4 192.168.2.1

# Set DNS
nmcli con mod eth1 ipv4.dns "8.8.8.8 8.8.4.4"

# Activate connection
nmcli con up eth1

Security Hardening

SELinux Configuration

# Verify SELinux is enforcing
getenforce

# Set to enforcing if not
sudo setenforce 1

# Make permanent
sudo sed -i 's/SELINUX=permissive/SELINUX=enforcing/' /etc/selinux/config

# Install SELinux tools
sudo dnf install -y setroubleshoot-server selinux-policy-devel

Firewall Setup

# Ensure firewalld is running
sudo systemctl enable --now firewalld

# Check current zones
sudo firewall-cmd --get-active-zones

# Add services
sudo firewall-cmd --permanent --add-service=ssh
sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https

# Add custom ports
sudo firewall-cmd --permanent --add-port=8080/tcp
sudo firewall-cmd --permanent --add-port=3306/tcp

# Reload rules
sudo firewall-cmd --reload

# List all rules
sudo firewall-cmd --list-all

SSH Hardening

# Backup SSH config
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.backup

# Edit configuration
sudo vim /etc/ssh/sshd_config

Recommended settings:

# Security settings
Protocol 2
PermitRootLogin no
PasswordAuthentication yes  # Disable after setting up keys
PubkeyAuthentication yes
PermitEmptyPasswords no
MaxAuthTries 3
ClientAliveInterval 300
ClientAliveCountMax 2

# Restrict users
AllowUsers admin user1 user2

# Use strong ciphers
Ciphers [email protected],[email protected],aes256-ctr,aes192-ctr,aes128-ctr
MACs [email protected],[email protected]

Apply changes:

# Test configuration
sudo sshd -t

# Restart SSH
sudo systemctl restart sshd

Repository Management

Enable Additional Repositories

# Install EPEL (Extra Packages for Enterprise Linux)
sudo dnf install -y epel-release

# Install ELRepo (for newer kernels and drivers)
sudo dnf install -y elrepo-release

# Enable PowerTools/CRB
sudo dnf config-manager --enable crb

# Enable HA and RS repos
sudo dnf config-manager --enable ha
sudo dnf config-manager --enable rs

# Update cache
sudo dnf makecache

Configure DNF/YUM

# Edit DNF configuration
sudo vim /etc/dnf/dnf.conf

Add optimizations:

[main]
gpgcheck=1
installonly_limit=3
clean_requirements_on_remove=True
best=True
skip_if_unavailable=False
fastestmirror=True
max_parallel_downloads=10
defaultyes=True
keepcache=0

System Services

Essential Services Setup

# Time synchronization
sudo systemctl enable --now chronyd
chronyc sources -v

# Enable cockpit (web management)
sudo dnf install -y cockpit
sudo systemctl enable --now cockpit.socket
sudo firewall-cmd --permanent --add-service=cockpit
sudo firewall-cmd --reload

# Performance monitoring
sudo systemctl enable --now sysstat

# Enable automatic updates (optional)
sudo dnf install -y dnf-automatic
sudo systemctl enable --now dnf-automatic.timer

Storage Configuration

LVM Management

# Display volume groups
sudo vgs

# Display logical volumes
sudo lvs

# Extend logical volume
sudo lvextend -L +10G /dev/rl/home
sudo xfs_growfs /home

# Create new logical volume
sudo lvcreate -L 20G -n data rl
sudo mkfs.xfs /dev/rl/data
sudo mkdir /data
echo '/dev/rl/data /data xfs defaults 0 0' | sudo tee -a /etc/fstab
sudo mount -a

Disk Monitoring

# Install monitoring tools
sudo dnf install -y smartmontools

# Enable SMART monitoring
sudo systemctl enable --now smartd

# Check disk health
sudo smartctl -a /dev/sda

Performance Optimization

Tuned Profiles

# Install and enable tuned
sudo dnf install -y tuned
sudo systemctl enable --now tuned

# List profiles
tuned-adm list

# Recommend profile
tuned-adm recommend

# Set profile based on workload
sudo tuned-adm profile virtual-guest      # For VMs
sudo tuned-adm profile throughput-performance  # For servers
sudo tuned-adm profile desktop           # For workstations

# Verify active profile
tuned-adm active

Kernel Parameters

# Create custom sysctl configuration
sudo vim /etc/sysctl.d/99-rocky-optimization.conf

Add optimization parameters:

# Network optimizations
net.core.rmem_max = 134217728
net.core.wmem_max = 134217728
net.ipv4.tcp_rmem = 4096 87380 134217728
net.ipv4.tcp_wmem = 4096 65536 134217728
net.core.netdev_max_backlog = 5000
net.ipv4.tcp_congestion_control = bbr

# VM optimizations
vm.swappiness = 10
vm.dirty_ratio = 15
vm.dirty_background_ratio = 5

# File system
fs.file-max = 2097152

# Apply settings
sudo sysctl -p /etc/sysctl.d/99-rocky-optimization.conf

Backup Configuration

System Backup Setup

# Install backup tools
sudo dnf install -y rsync tar

# Create backup script
sudo vim /usr/local/bin/system-backup.sh

Basic backup script:

#!/bin/bash
BACKUP_DIR="/backup"
DATE=$(date +%Y%m%d_%H%M%S)
HOSTNAME=$(hostname -s)

# Create backup directory
mkdir -p ${BACKUP_DIR}

# Backup system files
tar -czf ${BACKUP_DIR}/system_${HOSTNAME}_${DATE}.tar.gz \
    --exclude=/proc \
    --exclude=/sys \
    --exclude=/dev \
    --exclude=/tmp \
    --exclude=/var/tmp \
    --exclude=/backup \
    --exclude=/mnt \
    --exclude=/media \
    /

# Backup package list
rpm -qa > ${BACKUP_DIR}/packages_${HOSTNAME}_${DATE}.txt

# Remove old backups (keep 7 days)
find ${BACKUP_DIR} -name "*.tar.gz" -mtime +7 -delete

Make executable:

sudo chmod +x /usr/local/bin/system-backup.sh

# Add to cron
echo "0 2 * * * /usr/local/bin/system-backup.sh" | sudo crontab -

Troubleshooting Guide

Installation Issues

Boot Problems

# At GRUB menu, press 'e' to edit
# Add to kernel line:
systemd.unit=rescue.target

# Or for emergency mode:
systemd.unit=emergency.target

# Boot with modified parameters (Ctrl+X)

Network Issues

# Reset network
nmcli networking off
nmcli networking on

# Restart NetworkManager
sudo systemctl restart NetworkManager

# Check for errors
journalctl -u NetworkManager -n 50

Package Conflicts

# Clean all caches
sudo dnf clean all

# Rebuild cache
sudo dnf makecache

# Check for problems
sudo dnf check

# Remove orphaned packages
sudo dnf autoremove

# Repair RPM database
sudo rpm --rebuilddb

Recovery Procedures

Root Password Recovery

Reboot system
At GRUB menu, press ‘e’
Add rd.break to kernel line
Press Ctrl+X to boot
At prompt:

mount -o remount,rw /sysroot
chroot /sysroot
passwd root
touch /.autorelabel
exit
reboot

File System Repair

# Boot from installation media
# Select "Troubleshooting" → "Rescue"

# Check file systems
fsck -y /dev/sda1
xfs_repair /dev/mapper/rl-root

# Mount and chroot
mount /dev/mapper/rl-root /mnt/sysimage
mount /dev/sda1 /mnt/sysimage/boot
chroot /mnt/sysimage

Best Practices Summary

Documentation
- Document all configuration changes
- Maintain system inventory
- Keep network diagrams updated
Security
- Regular security updates
- Monitor logs daily
- Implement least privilege
- Use SELinux enforcing mode
Monitoring
- Set up system monitoring
- Configure log aggregation
- Implement alerting
- Regular health checks
Backup
- Test backup restoration
- Offsite backup storage
- Document recovery procedures
- Regular backup verification

Conclusion

Rocky Linux 9 provides a robust, enterprise-ready platform suitable for any workload. This guide covered the complete installation process, from initial planning through post-installation hardening and optimization. By following these procedures, you’ll have a secure, performant, and maintainable Rocky Linux system ready for production use.

Key takeaways:

Proper planning ensures smooth installation
Security should be configured from the start
Regular maintenance keeps systems healthy
Documentation is crucial for troubleshooting

With Rocky Linux 9 successfully installed and configured, you’re ready to deploy applications and services with confidence in a stable, community-supported enterprise platform.