I assume you have properly installed and configured Zend Server CE from the repository.

First of all you need to install automake:

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install automake

Install Xdebug with PECL as root:

# pecl install xdebug

Note: if you don’t have PECL in your path you can prepend the absolute path before the command

# /usr/local/zend/bin/pecl install xdebug

Now you must edit php.ini file.

sudo nano /usr/local/zend/etc/php.ini

Add these lines at the end of file:

; Xdebug
zend_extension = /usr/local/zend/lib/php_extensions/xdebug.so

Note: Xdebug is incompatible with theZend Debugger extension. To disable this component you can log into Zend Server control page at https://localhost:10082 and navigate to tab Server Setup > Components then turn off Zend Debugger. Remember to click the Restart PHP button to apply the changes.