Warning: require_once(PEAR.php): Failed to open stream: No such file or directory in /var/www/html/inc/DB.php on line 29

Fatal error: Uncaught Error: Failed opening required 'PEAR.php' (include_path='.:/usr/share/pear:/usr/share/php:/usr/share/pear:/usr/share/php') in /var/www/html/inc/DB.php:29 Stack trace: #0 /var/www/html/inc/lib/DB/.queserser.DB.class.php(31): require_once() #1 /var/www/html/inc/lib/DB/.contentsDB.class.php(2): require_once('...') #2 /var/www/html/inc/contentsConfig.php(3): require_once('...') #3 /var/www/html/examples/index.php(2): require_once('...') #4 {main} thrown in /var/www/html/inc/DB.php on line 29