Step by Step Zimbra 6.x installation on CetOS 5.x

First you need to install a fresh CentOS operating system, keeping almost everything as default state. In this installation note I'm assuming few things-

  • There is either a LARGE '/' partion or a LARGE '/opt' partition. Zimbra by  default is installed on /opt directory
  • I'm also assuming that the server is not sitting beehind a firewall (for example if it's reched by port/ip forwarding from firewall, it won't work). But there are some  additional tasks that can allow you to run it behind a firewall. But unfortunately, I won't cover that up here.
  • SELinux and Linux firewall, should be disabled for the time being.
  • You can install webmin, and from there you can create your custom firewall policy/rule- but you can always do this later, after post installation of Zimbra

Now let's start.

Now we need to shutoff some services that will interfere with ZCS.

chkconfig sendmail off
chkconfig ip6tables off
chkconfig iptables off

We need one package before we can continue:

yum install libtool-ltdl

This completes the base installation of CentOS. On the next page we will setup Split DNS which is essential for ZCS. Go ahead and reboot, and fill up that coffee cup.

This part of installation is working off of the assumption that you are behind a firewall. If you are not behind a firewall (not recommended) you can skip this part of the installation.

I need to give credit where it is due. The chroot portion of this tutorial is adapted from Sebastien Wains. His CentOS Bind Chroot tutorial can be found at The Split DNS tutorial is adapted from the Zimbra Wiki and can be found at

yum install bind bind-chroot bind-libs bind-utils

REMINDER: Be sure to use the ip address and hostname/FQDN that is appropriate for your installation.

Login to webmin and go Servers > BIND DNS Server > Edit config file.

put the following values-

options {
       directory "/var/named";
       dump-file "/var/named/data/cache_dump.db";
       statistics-file "/var/named/data/named_stats.txt";
forwarders { ; };
include "/etc/rndc.key";
// We are the master server for
zone "" {
 type master;
 file "/var/named/";

Next click "Create Master Zone" >

Domain Name- your domain name (FQDN of your hostname)

Email Address-

Click Create

Now you click on the newly created Master zone ( and do the following-

On ADDRESS- leave empty on NAME field, and give your server IP on the ADDRESS field

On MAILSERVER- leave empty on NAME field and give your server IP on the ADDRESS field, enter 10 on PRIORITY field

Restart your DNS  server.

Enable autostart for named.

chkconfig named on

To verify that it is working do the following:


It should return something similar to this:


Notice that the ip address returned is the same as the local machine. That means success.

Now we can move on to installing ZCS.

ZIMBRA need some dependencies and you have to install it before :

Package requirement :

yum install gmp libstdc++ compat-libstdc++-33 sysstat


First Step of the installation process, Download ZCS here


extract the archive and read the content in ZCS folder:

# tar -xvf zcs*
# cd zcs-6*
# ls -al

As you can see you have to execute the install script to start the installation of ZCS




./ –platform-override

As you can see the installation check your system and define what you need to install.

Now you can define what you want to install, but the best thing is to follow installer.

ZIMBRA ask you to confirm the installation :

Install anyway? [N] Y

The system will be modified.  Continue? [N] Y

All is left, is to select and change your admin password, apply configuration and save > Restart zimbra service

Voila! your Zimbra installation is completed.

Now you can log in to admin-


Resource and references: