Migrating from Centos 7 to AlmaLinux

As is well known, support for Centos 7 was discontinued in the summer of 2024, and the ISPManager 6 control panel can no longer run on a server with Centos 7 installed. This raises the question for many users: what should be done and which alternative should be chosen? The first thing to note is that migration is a very responsible process. Below, we will explain how to do it correctly. 

Server requirements

The key tools for migration are the Elevate utility and the Leapp framework, which ensure a smooth transition between distribution versions. 

Your server must meet the following requirements:

1. RAM: at least 4 GB.
2. Free disk space: at least 5 GB.
3. The grub, screen, and python3 packages must be installed.

How to prepare for migration?

The AlmaLinux operating system is considered as an alternative to Centos 7. Once you are ready to migrate to this OS, the first thing you need to do is make a backup. The migration process will not be painful (even if you make some mistakes at a certain stage) if a backup company is created. To do this, prepare a snapshot of the system and a copy of the databases. This will automatically protect you from unnecessary problems and hassles.  

Once the database is ready, check the current version of CentOS: 

To do this, run the command:

cat /etc/centos-release

If the OS requirements are not met, you need to update the system packages using the command:

yum update

Migration process: instructions

1. Run the Python script.
2. Once it has checked the requirements, the conversion process will begin.
3. Download and unzip the script. To do this, run: curl -o centos7-to-alma8.tgz "http://download.ispmanager.com/tools/centos7-to-alma8.tgz tar -xzvf centos7-to-alma8.tgz cd centos7-to-alma8
4. It is recommended to run the script itself in a separate virtual tab of the screen utility: screen python3 main.py --reboot

Then you just have to wait for the conversion process to complete, after which the server will go into a scheduled reboot. Keep in mind that the entire process can take a long time and requires special attention and caution. At the end, you can also view the original version of the configuration files at /var/config_backups/.

Possible problems and their solutions

Errors when converting databases

Converting MySQL databases below version 8.0.36 or MariaDB databases below version 5.5.68 may result in data corruption. 

Using encrypted partitions or the xfc ftype=0 parameter may cause conversion errors. 

Removing drivers

The floppy, pata_acpi, and sata_via drivers must be removed. 

Booting issues after migration

If the system does not boot, try booting into recovery mode or using the AlmaLinux live CD/USB. Use chroot to access the system and reinstall the boot loader (e.g., GRUB2). 

Applications not working

You should also check the application logs for errors. Make sure that all necessary libraries and dependencies are installed. 

What to do if the migration was successful?

1. Check the OS version with the command cat /etc/os-release.
2. Make sure that all services are working correctly.
3. Check the network settings and connection to external resources.

If specific applications were used (e.g., Afterlogic, PostgreSQL), consider possible changes after migration. For example, Afterlogic may be replaced with RoundCube, and PostgreSQL may require additional configuration.

It is also useful to know

1. Before migrating, update all packages in CentOS 7 to the latest available versions.
2. If you encounter difficulties with Leapp, check the logs in /var/log/leapp/upgrade.log and /root/centos7-to-alma8/convertation.log
3. After successful migration, create a report on the process in the file /root/centos7-to-alma8/convertation-report.txt
4. Migration can take a significant amount of time and requires careful attention. If the process ends with an error, fix the problems and run the
5. script again — it will continue from where it left off.

If you encounter specific problems and difficulties, it is worth referring to the official ISPmanager and AlmaLinux documentation.