How can I install APC on my cPanel VPS?

APC (Alternative PHP Cache) is a free and open opcode cache for PHP which offers a robust framework for optimising and caching your PHP code. It can provide a considerable performance boosts for your websites. Whilst it isn't supported through cPanel's EasyApache (like other caches such as xcache and eAccelerator), it's quite easy to install.

Before you consider installing APC you need to ensure your PHP handler is either set to DSO or FastCGI, as unfortunately suPHP is unsupported. For the best results consider running PHP as DSO + mod_ruid2 for optimal performance and security.

To install APC please run the following from SSH:

cd /usr/local/src

wget http://pecl.php.net/get/APC-3.1.8.tgz

tar -zxvf APC-3.1.8.tgz

cd APC-3.1.8

phpize

./configure --enable-apc --enable-apc-mmap --with-apxs --with-php-config=/usr/local/bin/php-config

make

make install

 # cd /usr/local/src

 # wget http://pecl.php.net/get/APC-3.1.9.tgz

# tar -zxvf APC-3.1.9.tgz

# cd APC-3.1.9

# phpize

# ./configure --enable-apc --enable-apc-mmap --with-apxs --with-php-config=/usr/local/bin/php-config

# make

# make install

Note: APC 3.1.9 was the latest stable release at the time this article was written, please check http://pecl.php.net/package/APC before proceeding to ensure you install the latest version.

Following your APC install, add the following lines to your global php.ini (/usr/local/lib/php.ini) to activate it:

extension="apc.so"

apc.enabled=1

apc.shm_segments=1

apc.shm_size=128

NB:Please remember that cPanel don't provide support for APC, but the benefit it can offer and the vast amount of information available on the internet about it can certainly make it worth it.