| ## Planning Sites for DCE Security Service Components The first thing that you do to configure the security service in your network is choose the sites for the master replica and any slave replicas of the registry. These sites will run secd, the security server. Machines running secd must be up and available at all times. It is especially important that the machine where the master replica runs be available throughout the network. The machine size that is required to run secd depends on the platform and operating system. As a very general rule, choose machines large enough to accommodate future growth of the registry database. The machines must have enough disk space for the registry database and enough backing store so that processes do not thrash. When you run the dce_config script, it will configure the master replica site to run the DCE host daemon (dced), which provides the endpoint mapper service for the local host, and any required CDS servers. ##