#1. Install file module (PHP 5.2.x)

cd /tmp/
wget http://downloads.zend.com/optimizer/3.3.9/ZendOptimizer-3.3.9-linux-glibc23-x86_64.tar.gz
tar xvfz ZendOptimizer-3.3.9-linux-glibc23-x86_64.tar.gz
cd ZendOptimizer-3.3.9-linux-glibc23-x86_64/data/5_2_x_comp/
mkdir /usr/local/lib/Zend
mv ZendOptimizer.so /usr/local/lib/Zend/

or PHP 5.3.x

cd /tmp/
wget http://downloads.zend.com/guard/5.5.0/ZendGuardLoader-php-5.3-linux-glibc23-x86_64.tar.gz
tar xvzf ZendGuardLoader-php-5.3-linux-glibc23-x86_64.tar.gz
mkdir /usr/local/lib/Zend
mv ZendGuardLoader-php-5.3-linux-glibc23-x86_64/php-5.3.x/ZendGuardLoader.so /usr/local/lib/Zend/

#2. Config module (PHP 5.2.x)

echo "zend_extension=/usr/local/lib/Zend/ZendOptimizer.so" >> /usr/local/lib/php.ini
echo "zend_optimizer.optimization_level=15" >> /usr/local/lib/php.ini
/etc/init.d/httpd restart

or PHP 5.3.x

echo "zend_extension=/usr/local/lib/Zend/ZendGuardLoader.so" >> /usr/local/lib/php.ini
/etc/init.d/httpd restart

#3. Check module

php -m
php -i | grep Zend
php -v

Good Luck ;)

share: How to Install Zend Optimize on Debian 5.0.x 64bit DirectAdmin installed