Os Rocky Alma 8

Key Features

CentOS 8 Migration Context

CentOS 8 reached EOL December 31, 2021, approximately 18 months early. This prompted mass migration to Rocky and AlmaLinux. A large portion of production v8 systems are converted CentOS 8 installs.

migrate2rocky.sh

curl -O https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
chmod +x migrate2rocky.sh
bash migrate2rocky.sh -r

# Verify
cat /etc/rocky-release
rpm -qa | grep centos  # should be empty

almalinux-deploy.sh

curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh
bash almalinux-deploy.sh

cat /etc/almalinux-release

ELevate (8 to 9)

AlmaLinux's ELevate supports in-place 8-to-9 upgrades. Rocky does not officially support in-place major upgrades.

# AlmaLinux 8 -> AlmaLinux 9
dnf install -y leapp-upgrade leapp-data-almalinux
leapp preupgrade
leapp upgrade
reboot

Residual CentOS Package Detection

rpm -qa | grep -iE 'centos'           # residual CentOS packages
rpm -qa --qf '%{NAME}-%{VERSION}-%{RELEASE}\n' | grep '\.centos\.'
dnf list extras                        # orphaned packages

Rocky SIGs (v8)

Common Pitfalls

1. Not running dnf distro-sync after migration -- packages remain signed with CentOS keys
2. Leftover CentOS repo files in /etc/yum.repos.d/ -- cause dnf errors
3. Assuming ELevate works for Rocky 8 to 9 -- Rocky does not officially support this
4. Ignoring orphaned packages -- dnf list extras shows packages not from any active repo
5. Missing CentOS GPG key cleanup -- old keys remain in RPM database
6. Migrating systems with cPanel/Plesk without checking compatibility -- can break control panels

Version Boundaries

• Kernel: 4.18
• Python: 3.6 default (3.8, 3.9 via module streams)
• OpenSSL: 1.1.1
• CRB: Named "PowerTools" in EL8
• Status: Security updates until May 2029

Reference Files

Load for deep knowledge:

• ../references/architecture.md -- rebuild process, Rocky vs Alma
• ../references/diagnostics.md -- distro detection, migration verification
• ../references/best-practices.md -- migration procedures, repo management