Overview

This article discusses how to install required prerequisite software for CentOS. You must complete these tasks before you install Magento CE 1.8 or later or Magento EE 1.13 or later.

Before you continue, make sure you familiarize yourself with the installation process discussed in Prerequisites.

Updating System Software

It's a good practice to update your repositories and optionally update system software.

Update repositories:

yum -y update

Optionally upgrade software. This might cause a system reboot.

yum -y upgrade

Apache

Magento requires Apache use server rewrites. You must also specify the type of directives that can be used in .htaccess, which Magento uses to specify rewrite rules.

Installing and configuring Apache is basically a three-step process: install the software, enable rewrites, and specify .htaccess directives.

Installing Apache

Install Apache 2 if you haven't already done so.

yum -y install httpd

Enabling Apache Rewrites

1. Open httpd.conf for editing.

   vim /etc/httpd/conf/httpd.conf

2. Locate the block that starts with:

   <Directory /var/www/html>

3. In that block, change the value of AllowOverride to All.
4. Save your changes to httpd.conf and exit the text editor.
5. Restart Apache.

   service httpd restart

PHP

Magento CE and EE support the following PHP versions:

• Magento CE 1.6.0.0–1.8.1.0 and Magento EE 1.11.0.0–1.13.1.0 support PHP 5.3 natively. They can be used with PHP 5.4 if you apply the PHP 5.4 patch.
• Magento CE 1.9.0.x and EE 1.14.0.x support PHP 5.4 natively. They are backward-compatible with PHP 5.3
• Magento CE 1.9.1 and EE 1.14.1 support PHP 5.5 natively. They are backward-compatible with PHP 5.4

We recommend you use the most recent PHP version supported by your version of Magento. For example, you should use PHP 5.5 with CE 1.9.1 or EE 1.14.1.

For more information about PHP, see:

• PHP 5.4 changelog
• PHP 5.5 changelog

Check with a system administrator or reference for your version of CentOS to see what PHP versions are available.

If you're installing Magento CE 1.9.1 or Magento EE 1.14.1, you can use PHP 5.5; otherwise, we recommend PHP 5.4. For certain versions of CE and EE, a patch is required to use PHP 5.4.

Enter the following command to see what version of PHP is currently running:

php -v

See one of the following sections for more information:

• Upgrading PHP
• Installing Required PHP Extensions
• Increasing the PHP memory Limit

Upgrading PHP

CentOS 6.x repositories have PHP 5.3. This section assumes you use either PHP 5.4 or 5.5. Make sure you understand which version of Magento CE or EE supports the PHP version to which you upgrade.

Before you start, verify you have PHP 5.3 installed:

php -v

If you already have the desired PHP version installed, you don't have to do anything.

If PHP is not installed, install PHP 5.3 using the following command:

yum -y install php php-xml

Continue with one of the following sections.

Upgrading to PHP 5.5

There is more than one way to upgrade CentOS 6.5 to PHP 5.5; the following is a suggestion only. Consult a reference for additional options.

Enter the following commands in the order shown.

cd /tmp
rpm -Uvh https://mirror.webtatic.com/yum/el6/latest.rpm
yum -y remove php-common-5.3.3-40.el6_6.x86_64
yum -y install php55w php55w-opcache

Skip the next section and continue with Installing Required PHP Extensions.

Upgrading to PHP 5.4

Enter the following commands to upgrade to PHP 5.4:

cd /tmp
rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
rpm -Uvh http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
yum --enablerepo=remi install httpd php php-common

The following resources are also available:

• kb.parallels
• stackoverflow
• remi repository

Installing Required PHP Extensions

The names of the PHP extensions you must install depend on the repository from which you installed PHP. Use one of the following commands:

PHP 5.5:

yum -y install php55w-xml php55w-mcrypt php55w-gd php55w-devel php55w-mysql php55w-mbstring

PHP 5.4:

yum -y install --enablerepo=remi php-mcrypt gd gd-devel php-gd php-mysql php54w-mbstring

Increasing the PHP Memory Limit

Increase memory_limit in php.ini to at least 512MB.

1. Open /etc/php.ini in a text editor.
2. Change memory_limit to:

   memory_limit = 512M

3. Save your changes and exit the text editor.

MySQL

This section discusses how to install and configure MySQL 5.6. CentOS 6.x repositories have MySQL 5.1; to install a different version of MySQL, see the MySQL documentation.

The following procedure is based on Install MySQL Server 5.6 in CentOS 6.x and Red Hat 6.x Linux.

1. Install the MySQL database:

   cd /tmp
   wget http://repo.mysql.com/mysql-community-release-el6-5.noarch.rpm
   rpm -ivh mysql-community-release-el6-5.noarch.rpm
   yum -y install mysql-server

2. Start MySQL.

   service mysqld start

3. Set a password for the root user and set other security-related options. Enter the following command and follow the prompts on your screen to complete the configuration.

   mysql_secure_installation

Next Steps

After installing the required prerequisite software, continue your installation with Preparing Your Server for Magento CE or EE.