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
xdebug.remote_enable=1
xdebug.remote_handler=dbgp
xdebug.remote_mode=req
xdebug.remote_host=127.0.0.1
xdebug.remote_port=9000
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.