If you are using RHEL or CentOS, you need to have the EPEL repository enabled. When it is enabled you can install the php memcached package with the following command
yum install php-pecl-memcached
If you are using RHEL or CentOS, you need to have the EPEL repository enabled. When it is enabled you can install the php memcached package with the following command
yum install php-pecl-memcached