WHM Features and System Requirements

cpanel-whm-logoWHM Overview

WHM is the ideal software solution, saving you precious money AND time. How? By streamlining many tasks that would otherwise involve spending hours on end performing tedious management tasks. An added benefit – the ability to match an existing company brand to the control panel.

Managing User Accounts

Certainly, if you’re looking at scaling your VPS or dedicated server to increase customer retention or promote new business, making it possible for clients to effectively manage their sites is key. Toward that end, WHM allows you to both create and manage user accounts AND set up pricing tiers.

Protecting Your Investment

The developers at WHM have engineered the utmost quality of security and server protection, designed entirely to protect your investment. With WHM, you’ll receive frequent updates AND analytics on your server.

Monitoring Your Server So You Know What’s Going On

Let’s face it – stuff can go wrong at any time of the day or night, when you least expect it. That’s called Murphy’s Law. If anything can go wrong, it will. It’s just a matter of when. With WHM, you’ll always know what’s happening on your servers 24/7.

WHM’s server monitoring tools make it possible to understand what’s happening on your server 24/7.

  • Resource utilization? You got it – they’re viewable.
  • Log file issues? WHM has a diagnosis feature to help resolve those problems.
  • Would love to configure automations? Done deal.
  • Third-party attacks? Built in protection enabled.

Facilitating Transfers and Backups

cPanel to cPanel migrations and transfers are a breeze, minimizing time to move from one server or provider to another. This takes the worry out of losing any data critical information.

Customized solutions catered to your clients

WHM contains some great auxiliary tools and features, providing your clients with a one-of-a-kind experience.

Branding your corporation or organization

Just ask any successful corporation how important branding is. WHM understands that, and allows you to incorporate your own images, colors and so on.

Just like WordPress, there are tons of plugins available to supplement WHM. Want to offer a tailored experience to your clients?


Component Minimum requirement
Hostname A registered fully-qualified hostname that does not match any of your server’s domains.
IP addresses
  • A valid IP address.
  • A valid subnet address
  • A default gateway IP address
Ethernet device A properly-configured Ethernet device with a static IP address and fully-qualified hostname.

You cannot use an IP address that a DHCP service dynamically assigns to your server.

Firewalls You must disable OS firewalls before you run the cPanel & WHM installation. When the installation process finishes, configure your firewall with a third-party client. We recommend that you use APF or CSF.


Red Hat® Enterprise Linux (RHEL), CloudLinux™, CentOS, and Amazon Linux distributions allow you to disable the firewall for the operating system’s installation configuration. We strongly recommend that you use this method.

Deactivate firewalls on CentOS, CloudLinux, and RHEL 6…

Deactivate firewalls on CentOS, CloudLinux, and RHEL 7…

Utilities You must disable NetworkManager before you run the cPanel & WHM installation. The Network Manager service automates the network’s settings and disrupts connections to the IP addresses that reside in the ipaliases module.


  • Run the following commands from the server’s console to prevent any interruption to network connectivity.
  • Exercise extreme caution when you run these commands. If you do not follow them exactly, your server may lose its network services.

Disable NetworkManager on CentOS, CloudLinux, or RHEL 5 or 6…

Disable NetworkManager on CentOS, CloudLinux, or RHEL 7…

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 below, but servers that host videos, music, or high-volume applications require more processing power, disk space, and RAM.


  • The cPanel & WHM installation and upgrade processes require at least 3 GB of additional disk space for staging purposes.
  • Before the installation process begins, the system checks to ensure that your server meets these minimum memory requirements. If your server does not meet these requirements, the installation process will return an error message and then exit.

Operating systems


cPanel, Inc. supports all of the official production release kernels for these operating systems.

We currently support CentOS versions 6.5 or later.


  • Installations of cPanel & WHM on CentOS servers must use CentOS version 6.5 or later.
  • We recommend that you use the minimal installer, especially if you choose to install CentOS 7.

Click for CentOS installation instructions…

We currently support CloudLinux versions 6 and 7.


For more information about CloudLinux installation, read CloudLinux’s Getting Started with CloudLinux OS documentation.

Click for more information and CloudLinux installation instructions…

We currently support Red Hat Enterprise Linux versions 6 and 7.


  • Installations of cPanel & WHM on RHEL servers must use RHEL version 6 or higher.
  • cPanel, Inc. does not support installation on Red Hat Update Infrastructure (RHUI) systems.

Click for more information and RHEL installation instructions…

We currently support Amazon Linux.

To install Amazon Linux, follow the instructions in the Amazon Web Services documentation.


  • We only support Amazon Linux on the official cPanel & WHM AMI. To find this AMI, navigate to the cPanel & WHM AMI download in the AWS marketplace.
  • To install cPanel & WHM in a CloudLinux AMI environment, you must download the CloudLinux AMI. To find this AMI, navigate to the CloudLinux AMI in the AWS marketplace. You cannot convert a cPanel & WHM AMI server to a CloudLinux server.
  • We strongly recommend that you do not install cPanel & WHM on servers that rely on snapshot data (for example, Amazon EC2 Spot Instances). When these servers revert to use snapshot data, the system detects this action as a uniqueness change. This behavior causes these servers’ cPanel & WHM licenses to lock due to the uniqueness changes for that server’s cPanel & WHM license. A locked license disables a cPanel & WHM server.


Ruby on Rails does not function on Amazon Linux servers and is not currently available on CentOS 7 servers.

Disable SELinux

If your server runs an operating system from a source other than the cPanel & WHM installer, you must disable SELinux to make your system compatible with cPanel & WHM.

To disable SELinux security features, use one of the following methods:

  • Use the graphical interface to disable SELinux while you configure your operating system, and then reboot the server.
  • Edit the /etc/selinux/config file to set the SELINUX parameter to disabled, and then reboot the server.

The contents of the /etc/selinux/config file should resemble the following example…


  • To run cPanel & WHM on your server, SELinux must remain disabled.
    • SELinux in enforcing mode does not allow cPanel & WHM to function properly. For more information about SELinux modes, read the SELinux Mode documentation.
    • While cPanel & WHM can function with SELinux in permissive mode, we recommend that you do not use it. Permissive mode generates a large number of log entries.
    • To check the status of SELinux on your server, run the sestatus command.
  • Do not transfer the SELinux configuration file between computers. It may destroy the file’s integrity.

IPv6 kernel support

cPanel & WHM and cPanel DNSONLY require that your kernel includes the ipv6 module, or includes that functionality directly within the kernel.

  • If your kernel does not include it in the ipv6 module, the AF_INET6 address family must also be available.
  • Most distributed kernels include this support by default. However, some users of custom kernels may experience problems.


If your kernel does not include the appropriate IPv6 support, the installation will fail.

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 yum -y install perl 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.


We strongly recommend that you allow your operating system’s distribution to control the system Perl installation. Do not customize this Perl installation.


When you install your operating system (OS), we recommend that you use the following filesystems:

  • CentOS, CloudLinux, and RHEL 7 — Use the XFS® or ext4 filesystems.
  • All other supported operating systems — Use an ext filesystem (ext3 or ext4).


We only develop and test cPanel & WHM on filesystems that support flock. Some network filesystems (for example, NFS) may require additional configuration in order to function properly. However, these configurations are difficult to implement successfully and we do not support them.


Partition OS RAM Minimum size
/ All supported operating systems. N/A Grow to fill disk (40 GB recommended, 20 GB minimum).


To host a greater number of accounts, allocate more disk space to this partition.

swap CentOS, CloudLinux, or RHEL 6 or 7, or Amazon Linux 2 GB or less Two times the amount of RAM on the server.
2 GB to 8 GB The same as the amount of RAM on the server.
8 GB to 64 GB Half the amount of RAM on the server.
64 GB or more 4 GB


Additional partitions are beneficial for some servers, especially servers with high email volume. The OS can only access a limited number of files per partition.


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:

Virtual environment Additional restrictions
KVM None.


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 and cPanel documentation.
Linux-VServer None.
Microsoft Server® 2008 Hyper-V, Microsoft Server 2012 Hyper-V cPanel only supports the drivers and configurations that Microsoft provides.
  • cPanel only supports stable releases.
  • CloudLinux is not compatible with OpenVZ.
Oracle VM VirtualBox, VirtualBox OSE None.
SmartOS cPanel & WHM detects this virtual environment and reports as functional, but we do not officially support it.
  • CloudLinux is not compatible with Virtuozzo.
  • We only support Virtuozzo version 6 and earlier. You may experience issues if you attempt to use Virtuozzo version 7
VMware® Server, VMware ESX Server None.
Xen, XenEnterprise™, XenExpress™, XenServer™ None.

Compatible browsers

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

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

  • Chrome (Mac®, Windows®, Linux)
  • Firefox (Mac, Windows, Linux)
  • Internet Explorer (Windows)
  • Safari® (Mac)

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


These browsers support some email features. The interfaces in cPanel & WHM will likely function, but you may notice minor defects or inconveniences that relate to specific functionality.

1  System Requirements – https://documentation.cpanel.net/display/ALD/Installation%20Guide%20-%20System%20Requirements#a5033bd443304f57a459d1b6da443666 Installation Guide



We’ve been in the web hosting industry for ten years, helping hundreds of clients succeed in what they do best and that’s running their business. We specialize in Virtual Private Servers (VPS) and dedicated servers, with data centers in Los Angeles and Denver.

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