PDOが動作しなかった問題

PHP Fatal error:  Call to a member function prepare() on a non-object in /opt/hoge/lib/db.inc on line 34

エラー発生個所から少し戻って、ハンドル取得箇所で例外をサボらず表示

<?
        try {
            $dbh = new PDO($dsn, $dbuser, $dbpass);
        } catch (PDOException $e) {
            var_dump($e);
            $dbh = null;
        }

object(PDOException)#2 (8) {
  ["message":protected]=>
  string(21) "could not find driver"

ドライバーが無い

$ php -r "phpinfo();" | grep -i pdo

pdo_mysqlがいないとき

/etc/php.d/pdo.ini,
/etc/php.d/pdo_sqlite.ini,
PDO
PDO support => enabled
PDO drivers => sqlite
pdo_sqlite
PDO Driver for SQLite 3.x => enabled

pdo_mysqlがいるとき

/etc/php.d/pdo.ini,
/etc/php.d/pdo_mysql.ini,
/etc/php.d/pdo_sqlite.ini,
PDO
PDO support => enabled
PDO drivers => mysql, sqlite
pdo_mysql
PDO Driver for MySQL => enabled
pdo_sqlite
PDO Driver for SQLite 3.x => enabled

http://mirror.centos.org/centos/6/updates/x86_64/Packages/

• php-mysql-5.3.3-27.el6_5.x86_64.rpm

# rpm -ivh php-mysql-5.3.3-27.el6_5.x86_64.rpm