YPVS

YPVS stands for Yellow Pages Virtual Server, a term encountered in historical UNIX and networking literature to describe a virtualized or abstracted instance of the Yellow Pages (YP) directory service. The Yellow Pages, later commonly known as NIS (Network Information Service), provided centralized maps of system information such as passwd, group, hosts, and services to client machines on a network. A YP server component, ypserv, distributed these maps to configured clients, enabling consistent user and host data across systems. YPVS is used in some discussions to denote a deployment model where one physical server presents multiple virtualized YP services or partitions, allowing separation of data domains or scaled management while still using the traditional YP/NIS protocol stack.

In practice, YP/NIS-based deployments rely on a collection of maps stored on the server and distributed to clients through the YP protocol. A virtualized variant would conceptually enable more flexible administration, such as isolating data for different organizational units or testing environments, without requiring separate physical servers for each YP domain. However, the term YPVS is not widely standardized and documentation varies; concrete implementations and best practices are seldom detailed in modern sources.

Today, YP/NIS has seen broad decline in favor of LDAP-based directory services, DNS, and other centralized management approaches. When encountered in contemporary contexts, YPVS is typically referenced as a historical or niche concept related to virtualized or partitioned YP/NIS deployments rather than a mainstream technology. See also Yellow Pages, NIS, ypserv, LDAP, DNS.