Overview

This document describes the system requirements for your cPanel & WHM installation on an Ubuntu® server.

You can install cPanel & WHM on Ubuntu version 20.04 LTS or Ubuntu 22.04 LTS.

Before you install cPanel & WHM, make certain that your Ubuntu system meets all of our minimum requirements for new installations.

License

Each cPanel & WHM server requires its own license. If you do not already own a license for cPanel & WHM, you can obtain one for your server’s IP address. To obtain a cPanel & WHM license, visit the cPanel Store.

Networking requirements

Hostname

Your hostname must meet the following requirements:

• Be a registered and fully-qualified domain name.
• Does not match any of your server’s domains.
• Be a maximum of 60 characters in length.
• Resolve to a valid IPv4 or IPv6 address.

IP addresses

Your system must meet the following requirements:

• Have a valid IP address.
• Have a 1:1 NAT and NAT loopback configuration if your server resides on a NAT-configured network.

Ethernet device

You must configure your Ethernet device with a static IP address and fully-qualified hostname. The system will detect and set up the Ethernet device during installation.

Firewalls

The installer will attempt to open the necessary ports during the installation process. We recommend that you disable OS firewalls before you run the cPanel & WHM installation. When the installation process finishes, we recommend that you then configure a firewall with a third-party client such as APF or CSF.

To deactivate firewalls on Ubuntu, run the following commands, where ~/firewall.rules represents the firewall rules file:

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iptables-save > ~/firewall.rules
systemctl stop ufw.service
systemctl disable ufw.service

Hardware requirements

Hardware considerations

When you choose a server, consider the following questions:

How many sites do you plan to host?

Servers that host a large number of websites with associated email addresses and databases require more processing power, disk space, and RAM.

What kind of web hosting do you plan to do?

You can run cPanel & WHM with the minimum requirements in the table above. However, servers that host videos, music, or high-volume applications require more processing power, disk space, and RAM.

If you plan to host CPU-intensive applications on a virtual machine, we recommend that you evaluate your CPU load usage. You may need to assign additional CPU cores to satisfy the processing requirements of high-performance applications.

Ubuntu versions

You can install cPanel & WHM on the following versions of Ubuntu:

• Ubuntu 20.04 LTS (Focal Fossa).
• Ubuntu 22.04 LTS (Jammy Jellyfish)

To install Ubuntu, read their Installing Ubuntu documentation.

Operating state

In Linux, the operating system possesses several levels of operating states. Each different level represents a system configuration and allows users to access different processes.

Verify and change the operating state

To verify the OS runlevel for Ubuntu, run the following command as the root user:

systemctl get-default

To change the OS runlevel for Ubuntu, run the following command as the root user, where TARGET.target represents the operating state target:

systemctl set-default TARGET.target

For a complete list of targets, visit Ask Ubuntu’s How do I change the runlevel on systemd? article.

SELinux and AppArmor

Do not install SELinux on your server. SELinux is not compatible with cPanel & WHM.

Ubuntu installations run AppArmor by default. AppArmor is compatible with cPanel & WHM. You do not need to disable AppArmor to install cPanel & WHM.

Perl installation

Perl must exist on your server before the installation script for cPanel & WHM can run successfully. If Perl does not exist during installation, the cPanel & WHM installer attempts to install Perl via the apt -y install perl perl-base command.

• If you see errors during this step of the installation process, read our Troubleshoot Your Installation documentation.

• For more information about Perl on your server, and which versions of Perl ship with specific operating systems, read our Guide to Perl in cPanel & WHM documentation. cPanel & WHM servers use multiple Perl environments.

Filesystems

When you install your operating system (OS), we recommend that you use the XFS® or ext4 filesystems.

Partitions

Inodes

In Linux, an inode is a filesystem object that contains the owner, permissions, and other important metadata. Every file, image, directory, email, and symbolic link on your server requires an inode.

• On average, files on webservers are usually smaller than on other types of servers. Therefore, we recommend that you allocate more than the default number of inodes on your server’s partitions.

• If you install everything on a single partition, the base cPanel & WHM or cPanel DNSOnly installation requires at least 1,000,000 inodes, plus at least 50,000 inodes per cPanel account that you plan to host.

Virtual environments

cPanel products support the following virtual environments with the following restrictions:

• KVM — No additional restrictions.

  Note:

  If you use a Linux bridge on a KVM server, you may experience problems with multicast routing.

  • These problems affect the server’s ability to resolve nodes on the network. For example, IPv6 Stateless Address Autoconfiguration (SLAAC) addresses may drop off intermittently, or the server may experience problems when it attempts to find the router.

  • To resolve this issue, set the multicast_router system knob value to 2. For more information, read the CentOS-virt mailing list thread.

• Linux Containers — cPanel & WHM requires additional configuration to run inside a Linux Container. For more information, read our Linux Containers documentation.

• Linux-VServer — No additional restrictions.

• Microsoft Server® 2008 Hyper-V, Microsoft Server 2012 Hyper-V — cPanel only supports the drivers and configurations that Microsoft® provides.

• OpenVZ

  • cPanel only supports stable releases.

• Oracle VM VirtualBox, VirtualBox OSE — No additional restrictions.

• QEMU — No additional restrictions.

• SmartOS — cPanel & WHM detects this virtual environment and reports as functional, but we do not officially support it.

• Virtuozzo™

  • We support Virtuozzo version 7 and earlier.
  • We only support Virtuozzo KVM and container environments.

• VMware® Server, VMware ESX Server — No additional restrictions.

• Xen, XenEnterprise™, XenExpress™, XenServer™ — No additional restrictions.

Compatible browsers

We specifically test cPanel & WHM with certain browsers to ensure compatibility. Other browsers will likely function, but may appear differently or experience issues with certain features.

We develop and test cPanel & WHM to function with the latest versions of the following browsers:

• Chrome™ (MacOS®, Microsoft® Windows®, Linux)

• Firefox (MacOS, Windows, Linux)

• Microsoft Edge (Windows)

• Safari® (MacOS)

Mobile versions of Firefox, Chrome, and Safari are also compatible with cPanel & WHM.

Databases

For more information about which database versions we support for Ubuntu, read our Supported MySQL/MariaDB versions documentation.

Nameservers

We only support the PowerDNS nameserver on Ubuntu. You cannot use any other nameserver.