Installing cPanel DNSOnly on AlmaLinux 10 in Proxmox LXC

With AlmaLinux 10 now officially supported by cPanel & WHM, many of us are moving our DNS clusters to the latest base. However, if you are performing a clean install inside a Proxmox LXC container, you might still run into a frustrating "Fatal Error 127" during the installation of universal hooks. This usually happens because the container environment is too minimal for the installer's scripts, or the specific AlmaLinux 10 hook repository isn't being reached correctly by the installation script.

After some testing, I found a specific sequence of commands that bypasses the "The background process Install [YUM universal hooks] failed with a fatal error: The subprocess reported error number 127 when it ended." and allows the DNSOnly installer to complete successfully on AlmaLinux 10.

1. Create a dummy fstab

Many cPanel scripts check for `/etc/fstab` to verify disk mounts. Since Proxmox LXC containers often don't have this file by default, we need to create it manually:

# touch /etc/fstab

2. Install Yum Utilities

Even though AlmaLinux 10 uses DNF, `yum-utils` provides essential compatibility tools required by the cPanel installation wrapper:

# yum -y install yum-utils

3. Manually Inject the Universal Hooks

This is the "secret sauce." If the automated installer fails to fetch the hooks, you can manually install the version 9 RPM. It is currently compatible enough with version 10 to satisfy the installer's requirements:

# rpm -ivh http://httpupdate.cpanel.net/cpanelsync/repos/CentOS/9/EA4/x86_64/yum-plugin-universal-hooks-0.1-15.21.1.cpanel.x86_64.rpm

4. Run the DNSOnly Installer

Now that the environment is prepared, you can pull the latest installer and run it. The error 127 should no longer appear.

# cd /home

# curl -o latest-dnsonly -L https://securedownloads.cpanel.net/latest-dnsonly

# sh latest-dnsonly

The Error 127 specifically refers to a "Subprocess reported error" because a hook script tried to call a binary that wasn't found in the minimal LXC template. By manually installing the `universal-hooks` RPM and creating the `fstab` file, you ensure all the paths and dependencies expected by cPanel are present before the main script starts.

While AlmaLinux 10 is the future, minimal container templates sometimes need a little manual help to work with enterprise software like WHM. Using this method, I was able to get my DNS cluster up and running on Proxmox in minutes.