Installing CentOS 6

Bill Giannikos

In this guide we will be providing an easy set of instructions for installing CentOS 6 on your computer. This guide already assumes you have prepared your computer for Linux or alternatively have followed the guides for VMware or VirtualBox if you plan to run CentOS as a virtual machine.

After booting off the CentOS 6 DVD (which is covered in the guides mentioned in the introduction) you will be presented with the above screen. The first option is correct for most people but if you find the first option doesn't work for you then you can try the second option for reduced graphics.

Here you can select if you would like to verify that the CD/DVD you are using doesn't contain errors. Press OK here to be on the safe side however if you are sure your media is fine then you can press Skip to save some time.

The CentOS 6 installer will now load and will begin by presenting you this welcome screen. Press Next.

Now select the language you would like to use and then press Next

Here you can select your keyboard type. Select the type of keyboard you have and click Next.

This screen indicates to CentOS what sort of storage device you are using. For nearly everybody this would be Basic Storage Device. Press Next when you have selected the appropriate option.

Depending on the currently setup of your hard drive(s) you may see this message. Select Re-initialize all to initialize your hard drive(s). This will delete all content on your drives so be careful.

You can now select the name of your computer. You also have the option to configure the network, however for a desktop installation I would leave this option for later. If on the other hand you are doing a server installation then you can configure the network from here. Enter what you like here and then click Next.

On this screen you can select the timezone appropriate to you.

You will also have an option labeled System clock uses UTC. This indicates whether the system clock in your computer is set to UTC time or local time. Typically if you are only going to run CentOS on this system then select this option. If you are going to be running Windows then de-select this option.

After you have selected the options appropriate to you click Next.

In this section you are able to enter the root password. This password is the administrator's password for the whole system. After entering your password twice (for verification purposes) click Next.

In this section you can specify how you would like to configure the hard drive(s). The first item selects the partitioning layout scheme with the options available being as follows:

• Use All Space - This clears everything off the hard drive and creates a default layout for CentOS using all the space available on the drive.
• Replace Existing Linux System(s) - This clears any current Linux partition off your hard drive and creates a default layout for CentOS in the free space made available. This leaves any non-Linux partition untouched.
• Shrink Current System - This allows you to resize any partitions you currently have on your hard drive and then creates the default CentOS layout in the available free space. This option is useful when you have a Windows partition using all the available hard drive space as it allows you to shrink the Windows partition to make room for CentOS.
• Use Free Space - This does not modify any partitions on your hard drive and just creates a default layout on the free space available.
• Create Custom Layout - This option is for advanced users. It allows you to create a custom layout for your CentOS installation.

The second option is if you would like to encrypt your system. The purpose of this option is to encrypt all the data on your hard drive to ensure that if your system is stolen the data on your computer can not be used. This works by having CentOS ask you for an encryption password each time you start it, if the person using the system does not know the password then the system will be unable to read the information on your drive. This option is typically only good for desktop installations, a server install will run into problems as someone needs to be physically at the terminal to enter the password each time the system reboots.

The Review and modify partitioning layout is for advanced users to modify the default CentOS layout.

After you have picked the options appropriate for your setup click Next.

After clicking Next you will get this confirmation box. Click on Write changes to disk to proceed with the partitioning.

Now you will be given the option on what type of installation you would like to do. You can also add additional repositories and customerize the installation if you wish, however most people wont need to do this at this stage. Select the installation type that is suitable for you and click Next.

Now the installation process will begin, this will take about 15 minutes. When the installation process is complete click on the Reboot button to end the installation wizard. This will restart the computer and boot into your new CentOS installation.

When booting into CentOS 6 for the first time you may be presented with this setup agent, depending on the installation type you chose. To begin press Forward.

This screen present you with the licensing agreement for CentOS. If you understand and agree with this license then click Forward.

Now you are presented with the Create User screen. Type in the username you would like to use, your name and the password you will be using. When this is done click Forward.

In this screen you are able to set the date and time. You may also like to select the Synchronize data and time over the network which will get the current date and time from servers from the Internet. After you have correctly set the current date and time click Forward.

In the Kdump section you can select whether to have logs active if a kernel issue occurs. For most people this option can be left as the default. When you have made your selection click Finish.

The Setup Agent is now complete and you are now able to log into your system.

Installation is almost complete but there is one very important step before being able to use CentOS and that is to install all the required security updates.

Log into your computer with the username and password you selected. Next ensure you have a working internet connection. If you are using a wireless connection you can configure the wireless using the network manager on the top right of the screen.

Next launch the Software Update program by going to System → Administration → Software Update.

CentOS has updated its package management system so you may first need to update those packages before updating the rest of the system. The Software Update program handles this for you but requires it to be run twice. When the updates list is presented click on Install Updates.

You will now get this confirmation prompt providing details about the key used to sign the packages you are about to download. You can verify that the signature identifier is correct and then click Yes to continue.

You will then be asked for your root password. Enter it and press Authenticate.

After the update is complete you will see this windows, click on the OK button and the Software Update program will close. You now need to restart the update program by again going to System → Administration → Software Update and refollow the steps above.

When the updates are complete restart your computer for these update to take effect.

To install the updates via the console follow these steps:

1. Log into the system as the root user.
2. Ensure you have a working internet connection.
3. Type in the following command:

   yum -y update

4. Retype the command above to ensure all updates are installed.
5. Reboot the computer.

Your system is now up to date.

Your CentOS 6 system is now fully installed and up to date. For further guides in configuring certain parts of CentOS please view our CentOS Guides section.