(1) In the DCE Cell Directory Service (CDS), the first instance of a specific directory in the namespace. After copies of the directory have been made, a different replica can be designated as the master, but only one master replica of a directory can exist at a time. CDS can create, update, and delete object entries and soft links in a master replica.
(2) In ClearCase MultiSite, the replica at which a mastered object can be modified or instances of the object can be created.