I installed like this
yum -y install memcached memcached-devel php-pecl-memcache
chkconfig memcached on
Options for memcached in folders /etc/sysconfig ? ? /etc/rc.d/init.d for memcached files
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="256" //any number you prefer
OPTIONS="-l 127.0.0.1"
Everything works fine several years