如果您的centos系统需要安装Zend Optimizer（比如virtualmin/webmin就没有安装zend optimizer），请复制下面1行命令，用root登录centos，粘贴，回车，一路回车即可完成安装zend optimizer(32位、64位的linux系统都支持！):

wget http://www.CTOHome.com/linux-vps-pack/zend.sh;sh ./zend.sh;

然后一路YES，OK和回车，安装就完成了。一般来说，不需要另外编辑php.ini文件就可以正常工作了。

如果您是64位的contos/linux系统，那么要注意安装64位的zend optimizer：

上面的1行命令会自动判断64位系统，并自动下载64位的zend optimizer!

Zend optimizer 3.3.9有一些新的改动，不需要安装了，直接在php.ini文件里面引用.so文件即可：

http://downloads.zend.com/optimizer/3.3.9/ZendOptimizer-3.3.9-linux-glibc23-i386.tar.gz  （32位）

http://downloads.zend.com/optimizer/3.3.9/ZendOptimizer-3.3.9-linux-glibc23-x386.tar.gz  （64位）

Zend optimizer 3.3.9使用说明：

ZendOptimizer-3.3.9-linux-glibc23-x86_64]# more README-ZendOptimizer
Zend Optimizer installation instructions
----------------------------------------
Important: if you are installing this product because you received a message from a web site telling you to install Zend Optimizer a
nd you are *not* the administrator of that web site STOP!.  You do not need to install this software. Instead, contact the website's
 system administrator and tell them that their website is displaying an error relating to Zend Optimizer and that they need to insta
ll Zend Optimizer in order to resolve this problem.

Release Information: This update is only relevant for PHP 5.2.X although this is a complete packagethat supports all other PHP versi
ons.

1. Extract the Zend Optimizer package.

2. Locate the ZendOptimizer.so (Unix) or ZendOptimizer.dll (Windows) file in the directory which
   corresponds to your version of PHP (4.3.x, 4.4.x, 5.0.x, 5.1.x, 5.2.x).

2. Add the following line to your php.ini file:
   Linux and Mac OS X:     zend_extension=<full_path_to_ZendOptimizer.so>
   Windows:                zend_extension_ts=<full_path_to_ZendOptimizer.dll>
   Windows non-thread safe: zend_extension=<full_path_to_ZendOptimizer.dll>
   (*) The Windows non-thread safe binary is only used with Zend Core 2.0.

3. Restart your Web server.

如果您需要修改某些参数，请参考下面的信息：

编辑/etc/php.ini

vi /etc/php.ini

找到：zend.ze1_compatibility_mode = Off

修改为：zend.ze1_compatibility_mode = On

保存退出！

编辑/etc/ispcp/fcgi/parts/php5/php.ini

找到：zend.ze1_compatibility_mode = Off

修改为：zend.ze1_compatibility_mode = On

在最后位置添加如下内容：

[Zend]
zend_extension_manager.optimizer=/usr/local/Zend/lib/Optimizer-3.3.3
zend_extension_manager.optimizer_ts=/usr/local/Zend/lib/Optimizer_TS-3.3.3
zend_optimizer.version=3.3.3
zend_extension=/usr/local/Zend/lib/ZendExtensionManager.so
zend_extension_ts=/usr/local/Zend/lib/ZendExtensionManager_TS.so

保存退出。然后同样以编辑/etc/ispcp/fcgi/parts/php5/php.ini的方式编辑/var/www/fcgi /domain.ltd/php5/php.ini以及/var/www/fcgi/master/php5/php.ini。至 此,zendoptimizer安装完成了！！所有的站点都可以使用ZendOptimizer!!!

备注：将zend.ze1_compatibility_mode设置成 On仅在PHP4下，如果您只安装了PHP5，建议不要修改，仍保持zend.ze1_compatibility_mode为Off状态， 即：zend.ze1_compatibility_mode = Off