centos6 安装zenddebug 无法启动，需要给依赖库做软链，yum找到指定版本依赖库并安装都不行，就得软链过去。

[root@ares ~]# service php-fpm restart
Stopping php-fpm:                                          [  OK  ]
Starting php-fpm: Failed loading /usr/lib64/php/modules/ZendDebugger.so:  libcrypto.so.0.9.8: cannot open shared object file: No such file or directory
                                                           [  OK  ]
[root@ares ~]# ln -s /usr/lib64/libcrypto.so.1.0.0 /usr/lib64/libcrypto.so.0.9.8
[root@ares ~]# service php-fpm restart                                          
Stopping php-fpm:                                          [  OK  ]
Starting php-fpm: Failed loading /usr/lib64/php/modules/ZendDebugger.so:  libcrypto.so.0.9.8: cannot open shared object file: No such file or directory
                                                           [  OK  ]
[root@ares ~]# ln -s /usr/lib64/libcrypto.so.1.0.1e /usr/lib64/libcrypto.so.0.9.8
[root@ares ~]# service php-fpm restart                                           
Stopping php-fpm:                                          [  OK  ]
Starting php-fpm:                                          [  OK  ]
[root@ares ~]#

参考：

http://dvlancer.com/36-how-to-install-zend-debugger-on-centos.html