# wget http://pecl.php.net/get/yaml-1.1.1.tgz
# tar yaml-1.1.1.tgz
# cd yaml-1.1.1
# phpize
# ./configure
# make
# make install

# yum install libyaml

echo 'extension=yaml.so' > /etc/php.d/yaml.ini

/etc/init.d/httpd configtest
/etc/init.d/httpd reload