How to Install WHM/cPanel on CentOS 6.6 64bit

This is a guide to install WHM/cPanel on CentOS 6.6 64bit. This setup is specific to this configuration, where we use CloudFlare as name servers.

Prep the OS

Start by updating the OS:

yum update

After the update, run the screen command:


Install cPanel

This is to ensure that the process doesn’t hang in case the ssh client disconnects. Install the latest stable version of WHM/cPanel.

cd /home && curl -o latest -L && sh latest

In case the ssh client disconnects. Just reconnect again on the same host and run this command:

screen -r

After the install completes, activate the license for WHM/cPanel:


Configure firewall for cPanel:


Install IonCube and Zend Guard

Install ioncube loader.

/scripts/phpextensionmgr install IonCubeLoader

Install Zend Guard Optimizer.


Login to https://$ip_address:2087/ to continue installation. The variable $ip_address could either be an ip assigned by your host or a fully qualified domain name.

Initial Configuration for cPanel

Login with the root credentials on the WHM control panel.
whm cpanel login
Update contact information. Make sure this is a working email address.
whm cpanel email
Configure the hostname. This should be a fully qualified domain (FQDN).
whm cpanel host name
Fill in the ip addresses for domain resolvers. We use Google’s nameservers since they are pretty reliable and free.
whm cpanel resolver
Configure ethernet device. Common setup will only have one ethernet device.
whm cpanel ethernet
Save and proceed to the next step.
Setup the ip address, just click on Skip This Step and Use Default Settings.
whm cpanel ip address
Since we’ve decided to use the cloudflare name servers, Name Server configuration is disabled.
whm cpanel name server
Set the cloudflare name servers here. Note that this is account specific:
whm cpanel setup name servers
Add A entry is skipped.
whm cpanel a entry
Save and go to step 5.
On the next window configure FTP, mail and cPHulk. Disable FTP to force SFTP only.
whm cpanel disable ftp
Use Dovecot as mail server.
whm cpanel dovecot
Enable cPHulk. Uncheck Install common set of Perl Modules.
whm cpanel cphulk
Save and go to step 6.
Enable disk quotas.
whm cpanel enable quotas
Save and continue.
On the next window, use the default options.
whm cpanel default options
Use default options as well with the new features.
whm cpanel new options
Save settings.
Once this is done, make sure to enable ionCube and ZenGuard on cPanel. Go to Server Configuration > Tweak Settings > PHP.
whm cpanel ioncube zend

Install Varnish

This install guide is for varnish version 3.x. Before installing varnish, change the port that Apache listens to, in this case 8080. It can be any other unused port. This can be accessed via Tweak Settings > System > Apache non-SSL IP/port.
whm cpanel install varnish
Once this is done, install varnish:

yum install varnish

In case this generates an error. Add the varnish repository:

rpm --nosignature -i

Should the install fail with a jemalloc error. Add the EPEL repo:

rpm -ivh

After install is complete, edit config file and change listening port to 80.

nano /etc/sysconfig/varnish

Edit this section.


In the same file, look for this


And replace with:

-s malloc,2G

This tells varnish to write the cache in memory instead of file and limit the size to 2GB. You’ll have to set the allocation smaller if you have limited memory.
Create the varnish config file.

cd /etc/varnish/
mv default.vcl default.vcl.orig
nano default.vcl

Use the following configuration. Replace the $host_ip_address var to your host’s ip address. NOTE: if you use localhost or, varnish will fail to work. The site will show the default page instead of the correct content.

backend default {
    .host = "$host_ip_address";
    .port = "8080";
sub vcl_recv {
    if (req.url ~ "\.(png|gif|jpg|swf|css|js)$") {
# strip the cookie before the image is inserted into cache.
sub vcl_fetch {
    if (req.url ~ "\.(png|gif|jpg|swf|css|js)$") {
    unset beresp.http.set-cookie;

Save config and start the varnish service.

service varnish start
chkconfig varnish on

To view varnish stat issue this command.

varnishstat -1

Give yourself a pat on the back. You can start adding accounts on cPanel.