DokuWiki » Infrastructure » Operating System » CentOS 6

h1. Install Procedure for CentOS 6.x

I want to say first that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take.

h2. Requirements

To install such a system you will need the following:

* Download the two CentOS 6.x DVDs from a mirror next to you (the list of mirrors can be found here: http://isoredirect.centos.org/centos/6/isos/x86_64/).

* a fast Internet connection.

h2. Preliminary Note

In this tutorial I use the hostname @server1.example.com@ with the IP address @192.168.0.100@ and the gateway @192.168.0.1@. These settings might differ for you, so you have to replace them where appropriate.

h2. Install The Base System

Boot from your first CentOS 6.x DVD. Press @<ENTER>@ at the boot prompt: 

!{width 500}centos6_inst01.png!

It can take a long time to test the installation media so we @skip@ this test here: 

!{width 500}centos6_inst02.png!

The welcome screen of the CentOS installer appears. Click on @Next@: 

!{width 500}centos6_inst03.png!

Choose your language next: 

!{width 500}centos6_inst04.png!

Select your keyboard layout: 

!{width 500}centos6_inst05.png!

Typically you will choose @Basic Storage Devices@ here

!{width 500}centos6_inst06.png!

I'm installing CentOS 6.x on a fresh system, so I answer @Re-initialize all@

!{width 500}centos6_inst07.png!

Set the hostname manually, e.g. @server1.example.com@

!{width 500}centos6_inst08.png!

On to the @configure network@. The default setting here is to configure the network interfaces with DHCP, but we are installing a server, so static IP addresses are not a bad idea... Click on the Edit button after selecting the interface.

!{width 500}centos6_inst09.png!

In the window that pops up uncheck //Dynamic IP configuration (DHCP)// and //Enable IPv6 support// and give your network card a static IP address (in this tutorial I'm using the IP address @192.168.0.100@ for demonstration purposes) and a suitable netmask (e.g. @255.255.255.0@; if you are not sure about the right values, http://www.subnetmask.info might help you) also enter a gateway (e.g. @192.168.0.1@) and up to two DNS servers (e.g. @8.8.8.8@ and @145.253.2.75@). By default all interfaces are **not** connected automatically, in most cases you want to change this.

!{width 500}centos6_inst10.png!

Choose your time zone:

!{width 500}centos6_inst11.png!

Give @root@ a password: 

!{width 500}centos6_inst12.png!

Now we must select a partitioning scheme for our installation. For simplicity's sake I select //use all space// and //Review and modify partitioning layout//. Then I hit @Next@: 

!{width 500}centos6_inst13.png!

This will result in a small /boot and a large / partition as well as a swap partition. Of course, you're free to partition your hard drive however you like it.

|_. type                  |_. logical volume name |_. mount point |_. size |

|_. small database server | lv_swap             | swap        |   512|

|_.                       | lv_home             | \home       |  1024|

|_.                       | lv_var_log          | \var\log    |  1024|

|_.                       | lv_var              | \var        |  3096|

|_.                       | lv_root             | \           |  4096|

Click on @Next@ to continue: 

!{width 500}centos6_inst14.png!

The hard drive is going to be formatted: 

!{width 500}centos6_inst15.png!

After the drive being formatted the partitioning layout needs to be writen to disk:

!{width 500}centos6_inst16.png!

As we have only one system on our disk, we leave the boot loader options with their defaults:

!{width 500}centos6_inst17.png!

Now we select the software we want to install. I usually choose @Minimal Desktop@, so we install the @GNOME-Desktop-Environment@. You are free to choose additional software repositories and via //Customize now// you can select some stuff to install on a package basis. Click on @Next@:

!{width 500}centos6_inst18.png!

The installation begins. This will take a few minutes:

!{width 500}centos6_inst19.png!

Finally, the installation is complete, and you can remove your CD or DVD from the computer and reboot it: 

!{width 500}centos6_inst20.png!

h2. Configuring The Base System

After a reboot the machine starts into a graphical basic settings environment. Click @Forward@ to continue.

!{width 500}centos6_setup01.png!

Here we get informed about the CentOS-License, most likely you want to @Agree@ and click @Forward@.

!{width 500}centos6_setup02.png!

you should always have a @user@ even in a server environment. Use your @root@ access only when necessary to prevent unintended changes to the system.

!{width 500}centos6_setup03.png!

Check Date and Time, as many services are very dependant on the timestamp you should set an approprate time-server or even better a time-server-pool. If you have internet access and are based in germany you might want to use following public NTP-server-pool.

<pre><code class="bash">

0.de.pool.ntp.org

1.de.pool.ntp.org

2.de.pool.ntp.org

3.de.pool.ntp.org

</code></pre>

check www.ntp.org for details. If you don't have access to a public NTP-server ask your admin for a local NTP-server.

!{width 500}centos6_setup04.png!

@Kdump@ is the Crash-Kernel environment. If you have less than 4GB RAM, you will get following Error-Message:

!{width 500}centos6_setup05.png!

If you @enable kdump@, make sure to assign at 384MB least, the default 128MB are not enough and will result in a bootlog-error. We don't need any more for our basic installation. Let's go @Finish@

!{width 500}centos6_setup06.png!

Welcome to your GNOME-Desktop-Environment.

After finishing our installation let's login the very first time.

Unlike previous CentOS-Versions there is direct no @root@-login to the graphical environment.

!{width 500}centos6_update01.png!

We change the screen to a text console via @CTRL-ALT-F2@

Please provide your username @root@. Do you still remember the password you thought of a few minutes ago?

!{width 500}centos6_update02.png!

get all the latest updates via @yum update@

!{width 500}centos6_update03.png!

h2. Post Installation Steps

h3. Install additional packages

With @minimal Desktop@ the most important packages are already installed. If you are curious about installed and available package-groups use

<pre><code class="bash">

yum grouplist

</code></pre>

and install additional groups via

<pre><code class="bash">

yum groupinstall "xxx"

</code></pre>