TUTORIALS • LINUX • OS MIGRATION

How to Migrate CentOS 7, CentOS 8 and Rocky Linux to AlmaLinux — Plus Upgrade AlmaLinux 9 to 10

A practical migration guide for Linux administrators: choose the supported path, prepare backups and console access, convert supported Enterprise Linux systems with almalinux-deploy, and perform major-version upgrades with ELevate and Leapp.

Author: Khurram Shahzad

Post type: Tutorials

Focus: Linux migration

Level: Intermediate / Advanced

Updated: Oct 17, 2026

Important: conversion and major-version upgrade are different tasks

almalinux-deploy converts supported Enterprise Linux distributions to AlmaLinux on the same major version—for example, CentOS Linux 8.4+ or Rocky Linux 8/9/10 to the corresponding AlmaLinux major version. It is not the CentOS 7-to-AlmaLinux 10 upgrade method. CentOS 7 needs a staged ELevate path: CentOS 7 → AlmaLinux 8 → AlmaLinux 9 → AlmaLinux 10. Review the official guide before attempting this multi-stage path.

Choose the Right Migration Path First

Do not run a conversion script before confirming your current OS, target release, architecture, repositories, bootloader and application compatibility. The supported path determines which tool and commands to use.

EL 7 → 10PLAN EACH STAGE

Same-Major Conversion

Use almalinux-deploy for supported CentOS 8, Rocky Linux and other listed EL systems.

Major-Version Upgrade

Use ELevate/Leapp for the documented CentOS 7 and AlmaLinux 9-to-10 upgrade paths.

Protect Recovery Access

Back up, test a clone, keep a console session and resolve pre-upgrade blockers before proceeding.

1. Migration Path Decision Table

Start with the installed distribution and version. The AlmaLinux migration tool’s published support list includes CentOS Linux 8.4 and later, CentOS Stream 8/9/10, and Rocky Linux 8/9/10. CentOS 7 is not in the supported list for almalinux-deploy; use the documented ELevate route instead.

Current system	Target	Method	Important note
CentOS Linux 8.4+	AlmaLinux 8	`almalinux-deploy`	CentOS Linux 8 is EOL; repository/Vault repair may be required first.
CentOS Stream 8	AlmaLinux 8	Check current migration-tool support and release notes	Confirm exact source version and target path.
Rocky Linux 8	AlmaLinux 8	`almalinux-deploy`	Same-major conversion, not an EL9/10 upgrade.
Rocky Linux 9	AlmaLinux 9	`almalinux-deploy`	Validate third-party repositories and application support.
Rocky Linux 10	AlmaLinux 10	`almalinux-deploy`	Confirm exact release and architecture in current README.
CentOS 7	AlmaLinux 10	ELevate staged upgrade	CentOS 7 → AlmaLinux 8 → AlmaLinux 9 → AlmaLinux 10.
AlmaLinux 9	AlmaLinux 10	ELevate/Leapp	Run pre-upgrade analysis and fix inhibitors first.

Migration is not the same as upgrade. A same-major conversion changes the distribution while retaining the major version. A major-version upgrade changes the OS generation and can affect packages, libraries, boot configuration, security policy and applications.

2. Pre-Migration Checklist

These procedures can alter repositories, packages, boot files and the running kernel. Use them only after validating the path against official documentation for your exact source and target releases.

Back up the system. Create a tested full backup or hypervisor snapshot. A snapshot alone may not protect external databases, mounted storage or remote services.
Test a clone first. Rehearse the entire procedure on a cloned VM or staging server.
Keep console access. Use IPMI, iLO, iDRAC, hypervisor console or physical access. If using SSH, run inside tmux or screen.
Check disk space. Ensure free space in /, /var, /boot and package caches.
Inventory repositories and packages. Record third-party repositories, custom RPMs, kernel modules, database versions, web stack, monitoring, backup and security agents.
Check vendor support. Confirm applications support the target AlmaLinux release and upgrade path.
Schedule downtime and prepare rollback. Define maintenance window and rollback criteria.

Capture the current system state

cat /etc/os-release
cat /etc/redhat-release
uname -r
uname -m
df -h
df -h /boot
lsblk
sudo dnf repolist --enabled 2>/dev/null || sudo yum repolist enabled
rpm -qa | sort > "$HOME/packages-before-migration.txt"

Save this output outside the server as well. The package list is an inventory aid, not a guarantee that every third-party package will migrate successfully.

3. Migrate CentOS 8 to AlmaLinux with almalinux-deploy

The official AlmaLinux migration guide supports conversion from CentOS Linux 8.4 or later. CentOS Linux 8 has reached end of life, so normal mirror lists may no longer work; repository repair or the script’s documented CentOS 8 handling may be necessary. Do not apply old repository commands blindly to CentOS Stream or another minor release.

CentOS 8 source requirementConfirm you are running CentOS Linux 8.4 or later and read the current “CentOS 8 Migration Notes” in the official AlmaLinux guide. If the host is below 8.4, follow the official preparation steps before conversion.

Update and reboot if repositories permit

sudo dnf update -y
sudo reboot

Reconnect through the server console after reboot and verify the system is healthy. If EOL repositories are unavailable, follow the official guide’s Vault notes or documented -f option instead of guessing repository URLs.

Download the official migration script

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

Download only from the official AlmaLinux GitHub repository. Review the current README and script before running it.

Run the conversion

sudo bash almalinux-deploy.sh

If CentOS 8 repositories need the script’s documented repair behavior, the project documentation describes sudo bash almalinux-deploy.sh -f. Use that option only after reading the current official notes and confirming it applies to your source system.

Check output and reboot

Review the full output for errors. A successful run reports “Migration to AlmaLinux is completed.” Then reboot:

sudo reboot

Verify distribution and boot entry

cat /etc/redhat-release
cat /etc/os-release
sudo grubby --info DEFAULT | grep AlmaLinux

Confirm the system reports AlmaLinux and the default boot entry points to an AlmaLinux kernel. Test networking, storage, SSH, applications, monitoring and backups.

Official procedure: AlmaLinux Migration Guide and almalinux-deploy project README.

4. Migrate Rocky Linux to AlmaLinux

The AlmaLinux migration tool lists Rocky Linux 8, 9 and 10 as supported source systems. This is a same-major conversion: Rocky Linux 9 to AlmaLinux 9, for example. Moving Rocky 8 to AlmaLinux 9 or 10 also requires a major-version upgrade plan.

Check exact release and architectureThe support list can change. Compare your installed Rocky Linux version and CPU architecture with the current README. The tool requires root privileges, sufficient disk space, supported GRUB2 boot configuration for bootable systems and reliable console access.

Update Rocky Linux

sudo dnf update -y
sudo reboot

After reboot, confirm system health and review any pinned package versions or third-party repositories.

Download the official script

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

Use a stable console or persistent SSH session such as tmux.

Run almalinux-deploy

sudo bash almalinux-deploy.sh

Monitor the output. If it exits with an error, investigate the reported issue instead of repeatedly rerunning it.

Reboot and validate

sudo reboot

# After logging in:
cat /etc/redhat-release
cat /etc/os-release
uname -r
sudo grubby --info DEFAULT | grep AlmaLinux

Verify the release, kernel and boot entry. Test application health, networking, firewalls, SELinux, monitoring and backup jobs.

Official references: almalinux-deploy on GitHub and the AlmaLinux Migration Guide.

5. Migrate CentOS 7 to AlmaLinux

CentOS 7 is not a direct source for the almalinux-deploy conversion flow. AlmaLinux documents a staged in-place upgrade using ELevate and Leapp. To reach AlmaLinux 10, the sequence is:

Stage	Source → target	Method	After each stage
1	CentOS 7 → AlmaLinux 8	ELevate / Leapp EL7-to-EL8	Reboot, validate services, review leftover EL7 packages.
2	AlmaLinux 8 → AlmaLinux 9	ELevate / Leapp EL8-to-EL9	Resolve blockers, reboot and validate applications.
3	AlmaLinux 9 → AlmaLinux 10	ELevate / Leapp EL9-to-EL10	Resolve blockers, reboot and run full post-upgrade checks.

Do not skip stages or run all stages as one script. Each stage has separate pre-upgrade checks, package changes, reboots and post-upgrade validation. Stop if a stage is unsupported for your architecture, repositories or applications.

Stage 1: prepare CentOS 7

CentOS 7 repositories are offline. The official AlmaLinux guide provides a CentOS 7 repository configuration for ELevate. Follow the current guide for your exact source system; do not substitute generic repository files or commands intended for CentOS 8.

Start with the official ELevate CentOS 7 to AlmaLinux 10 guide. It contains the EL7-to-EL8 steps and subsequent preparation notes.

Stage 2: upgrade AlmaLinux 8 to AlmaLinux 9

After Stage 1 succeeds, confirm the machine boots into AlmaLinux 8. Review the official instructions for cleaning up leftover EL7 packages and removing stale exclude= entries related to Leapp/ELevate where instructed. Install the documented packages, run pre-upgrade analysis, review the report and answer file, and resolve blockers before the upgrade.

Stage 3: upgrade AlmaLinux 9 to AlmaLinux 10

Once AlmaLinux 9 is stable, follow the official EL9-to-EL10 section in the same guide. Do not assume third-party repositories, databases, kernel modules or security agents will be compatible with AlmaLinux 10.

Why this article does not paste one universal CentOS 7 command sequence: this path is long and sensitive to repository state, package leftovers and ELevate version. The authoritative AlmaLinux guide maintains stage-specific commands and known issues; using that live procedure is safer than freezing a potentially stale command sequence into a general tutorial.

6. Upgrade AlmaLinux 9 to AlmaLinux 10

AlmaLinux documents in-place major-version upgrades using ELevate and Leapp. Success is not guaranteed simply because the source is AlmaLinux 9: review the pre-upgrade report, resolve inhibitors, and check third-party software compatibility.

Production warningTake a tested backup and, for VMs, a suitable snapshot or clone. Confirm out-of-band console access and a rollback plan. The procedure requires downtime and may leave third-party packages unavailable for the target release.

Update AlmaLinux 9 and reboot

sudo dnf update -y
sudo reboot

After reboot, verify application health and ensure no pending maintenance or repository issue remains.

Install ELevate and migration packages

Use the stable ELevate instructions for AlmaLinux 9 in the official quickstart guide. The documented package installation is:

sudo dnf install -y https://repo.almalinux.org/elevate/elevate-release-latest-el$(rpm --eval %rhel).noarch.rpm
sudo dnf install -y leapp-upgrade leapp-data-almalinux

Confirm the current official guide still specifies these package names and repository URL before execution; use the guide’s current command if it differs.

Run the pre-upgrade assessment

sudo leapp preupgrade
sudo less /var/log/leapp/leapp-report.txt
sudo less /var/log/leapp/answerfile

Review inhibitors, required answers and recommendations. Fix blockers and answer Leapp questions only after understanding their impact. Repeat the assessment until blockers are resolved; do not blindly accept changes.

Start the upgrade

Proceed only when pre-upgrade checks are clear and the rollback plan is ready:

sudo leapp upgrade

Follow the official instructions for the resulting reboot and upgrade boot entry. Do not interrupt the process; keep console access available.

Reboot and verify AlmaLinux 10

sudo reboot

# After login:
cat /etc/os-release
cat /etc/redhat-release
uname -r
sudo dnf repolist --enabled
sudo dnf check

Review Leapp logs, inspect leftover EL9 packages, restore required repositories using supported AlmaLinux 10 versions, and test every critical application.

Architecture noteCheck ELevate support for your CPU architecture and target image. The project notes specific limitations for x86_64_v2 upgrades to AlmaLinux 10; do not assume every hardware baseline uses the same migration package.

Official references: ELevate Quickstart Guide, CentOS 7 to AlmaLinux 10 guide and ELevate project overview.

7. Post-Migration Validation Checklist

Do not consider migration complete simply because the OS boots. Confirm distribution, kernel, repositories and workloads, then check service-specific logs.

Confirm distribution and major version using cat /etc/os-release.
Confirm running kernel and default boot entry.
Check package-manager health and enabled repositories.
Verify IP address, routing, DNS, time synchronization and firewall rules.
Check SELinux mode and investigate denials instead of disabling SELinux as a shortcut.
Verify SSH, user access, sudo permissions and scheduled jobs.
Test databases, web services, application services and custom systemd units.
Check monitoring, logging, backup agents and security tools.
Review migration logs and packages left from the previous OS version.
Run application smoke tests and take a new backup after successful validation.

cat /etc/os-release
uname -r
sudo dnf check
sudo systemctl --failed
sudo journalctl -p err -b --no-pager

These are general validation commands; service names and package-manager behavior vary by release. Save the outputs and compare them with your pre-migration baseline.

8. Common Migration Problems

CentOS 8 repository errors

CentOS Linux 8 is EOL. Follow the official guide’s Vault and -f notes only when they match your source version. Do not reuse CentOS Linux 8 edits on CentOS Stream.

Migration script exits early

Read the full output; verify source version, architecture, root privileges, free disk space, repositories and GRUB2 support. Resolve the specific error before retrying.

Leapp reports inhibitors

Read /var/log/leapp/leapp-report.txt and the answer file. Fix blockers according to the official guide, then rerun preupgrade.

Third-party app stops working

Check vendor support for the target release, restore correct repository configuration and use supported target-release packages. Avoid forcing old RPMs onto the new OS.

System does not boot

Use hypervisor or out-of-band console. Inspect boot entries and logs, follow official recovery instructions or revert to tested backup. Do not remove old kernels before validation.

SSH session disconnects

Use a reliable console or persistent terminal such as tmux/screen. A dropped SSH connection does not confirm whether a package transaction succeeded.

Frequently Asked Questions

Can I migrate CentOS 7 directly to AlmaLinux 10 with almalinux-deploy?

No. CentOS 7 is not a supported direct source for the same-major conversion tool. AlmaLinux documents a staged ELevate path: CentOS 7 to AlmaLinux 8, then 8 to 9, then 9 to 10.

Does almalinux-deploy support CentOS 8?

The official tool supports CentOS Linux 8.4 and later. Because CentOS Linux 8 is end-of-life, repository configuration may need attention. Follow the official guide for your exact source release.

Can I convert Rocky Linux 9 to AlmaLinux 9?

Yes, Rocky Linux 9 is included in the tool’s published supported-system list for same-major conversion. Confirm the current README, architecture, bootloader and third-party application compatibility first.

Can almalinux-deploy upgrade Rocky Linux 8 to AlmaLinux 10?

Do not treat it as a direct major-version upgrader. The tool converts supported systems to AlmaLinux on the corresponding major version. Plan major-version upgrades separately with official supported tooling.

How do I upgrade AlmaLinux 9 to AlmaLinux 10?

Use the official ELevate/Leapp procedure: update and reboot AlmaLinux 9, install the documented migration packages, run leapp preupgrade, review and resolve the report and answer file, run leapp upgrade, reboot and validate.

Is an in-place migration risk-free?

No. Repository conflicts, third-party packages, bootloader issues and application incompatibilities can cause failures. Test on a clone, maintain backups and console access, and plan rollback.

Will my applications and data remain intact?

No general guide can guarantee every custom application, repository or configuration will work unchanged. Back up data and test the exact workload on a clone before production migration.

Where can I learn to install AlmaLinux 10 from scratch?

See our How to Install AlmaLinux 10 tutorial for a fresh installation workflow. A clean install and data migration may be preferable when the source is highly customized or its in-place path is unsupported.

Conclusion

The safest AlmaLinux migration starts by choosing the correct tool for the installed OS. Use almalinux-deploy for supported same-major conversions such as CentOS Linux 8.4+ or Rocky Linux 8/9/10 to the corresponding AlmaLinux release. Use ELevate/Leapp for documented major-version upgrade paths, including AlmaLinux 9 to 10.

CentOS 7 requires particular care because reaching AlmaLinux 10 is a multi-stage upgrade, not a one-command conversion. Follow the official stage-specific guide, back up and test the process, keep console access, resolve pre-upgrade blockers and validate applications after each reboot. If the existing system is highly customized or its path is unsupported, consider a clean AlmaLinux installation and controlled data/application migration.

Migration checklistIdentify source and target → Verify supported path → Back up and test a clone → Ensure console access and disk space → Run the matching tool → Review logs and reboot → Validate packages, boot, network, security and applications → Take a new backup.

Planning a Fresh AlmaLinux 10 Deployment?

Read the VMoreCloud installation tutorial before building your new server or lab VM.

How to Install AlmaLinux 10 →

Official Sources & Further Reading

AlmaLinux Migration Guide — supported source systems, conversion steps, CentOS 8 notes and validation.
AlmaLinux/almalinux-deploy on GitHub — current supported systems, requirements and usage.
ELevate Project overview — supported major-version upgrade paths.
ELevate Quickstart Guide — in-place upgrade workflow and pre-upgrade checks.
ELevate CentOS 7 to AlmaLinux 10 guide — stage-specific process and known issues.
VMoreCloud: How to Install AlmaLinux 10 — related fresh-install tutorial.

Khurram Shahzad

Hybrid Cloud & Virtualization Engineer

Hybrid Cloud & Virtualization Engineer specializing in VMware, Azure, AWS, Windows Server, Microsoft 365, Linux, networking, backup & disaster recovery. I share practical guides, technical projects and insights into modern IT infrastructure through VMoreCloud.

Explore more VMoreCloud tutorials →

Technical disclaimer: Migration commands and support matrices can change. This tutorial is based on official AlmaLinux documentation available at review time, but cannot guarantee success on every customized host. Read the current official guide for your source version, target release and architecture. Test first, keep backups, and do not perform an untested in-place upgrade on production systems.