为提高效率，提问时请提供以下信息，问题描述清晰可优先响应。
【DM版本】:DM8
【操作系统】：centos7
【CPU】: vmware虚拟机
【问题描述】*：php7.2.33配置php.ini后，httpd服务启动不了

php版本：
[root@MiWiFi-CR6608-srv php_pdo]# php -v
PHP 7.2.33 (cli) (built: Aug 11 2020 15:38:39) ( NTS )
Copyright © 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright © 1998-2018 Zend Technologies

dm安装路径：
[root@MiWiFi-CR6608-srv php_pdo]# find / -name libphp72_dm.so
/home/dmdba/dmdbms/drivers/php_pdo/libphp72_dm.so
[root@MiWiFi-CR6608-srv php_pdo]# find / -name php_pdo
/home/dmdba/dmdbms/drivers/php_pdo

在/etc/php.ini文件添加以下内容：
[PHP_DM]
extension_dir =“/home/dmdba/dmdbms/drivers/php_pdo”
extension=libphp72_dm.so
[dm]
dm.port=5236
dm.allow_persistent = 1
dm.max_persistent = -1
dm.max_links = -1
dm.default_host = localhost
dm.default_db = SYSTEM
dm.default_user = SYSDBA
dm.default_pw = SYSDBA
dm.connect_timeout = 10
dm.defaultlrl = 4096
dm.defaultbinmode = 1
dm.check_persistent = ON

重启httpd服务后，启动不起来，提示错误如下：
PHP Warning: PHP Startup: Unable to load dynamic library ‘iconv.so’ (tried: /home/dmdba/dmdbms/drivers/php_pdo/iconv.so (/home/dmdba/dmdbms/drivers/php_pdo/iconv.so: cannot open shared object file: No such file or directory), /home/dmdba/dmdbms/drivers/php_pdo/iconv.so.so (/home/dmdba/dmdbms/drivers/php_pdo/iconv.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
PHP Warning: PHP Startup: Unable to load dynamic library ‘json.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘mbstring.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘mysqlnd.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘mysqlnd_mysqli.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘pdo.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘pdo_mysqlnd.so’
PHP Warning: PHP Startup: Unable to load dynamic library ‘pdo_sqlite.so’
PHP Fatal error: Unable to start DM module in Unknown on line 0
[root@MiWiFi-CR6608-srv php_pdo]#