Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!mordor!jdb From: jdb@mordor.s1.gov (John Bruner) Newsgroups: comp.unix.wizards Subject: Re: YP required with NFS? Message-ID: <851@mordor.s1.gov> Date: Wed, 14-Jan-87 14:21:30 EST Article-I.D.: mordor.851 Posted: Wed Jan 14 14:21:30 1987 Date-Received: Thu, 15-Jan-87 00:46:27 EST References: <2231@brl-adm.ARPA> <59000002@gorgo.UUCP> Reply-To: jdb@mordor.UUCP (John Bruner) Organization: S-1 Project, LLNL Lines: 23 I don't have any great love for YP (in fact, I really dislike it), but a YP-like scheme can address some problems which symlinks across remotely-mounted filesystems cannot. In a large network environment some files (e.g. the password file, the host table if you don't use the name daemon, the mail aliases file) are so large that a linear search of the ASCII file is too slow. 4.3BSD handles this by creating dbm-format files that can be accessed quickly. However, these binary files cannot be used in a heterogenous network environment (e.g. by both Suns and VAXes). YP solves this by creating dbm-format files and interposing an intermediate process (the YP server) to access them. Since YP is built upon RPC, multiple non-identical machines have a uniform interface to the data. BTW, has anyone noticed that the resolver library routines are absent from Sun 3.2's libc.a? All hostname lookups are supposed to go through the YP server, which will contact the name daemon if it needs to. Apparently Sun figured that noone would want to access the nameserver directly (e.g. to obtain MX RR's). (On our machines, I compiled the resolver library from 4.3BSD and installed it as "libresolv.a".) -- John Bruner (S-1 Project, Lawrence Livermore National Laboratory) MILNET: jdb@mordor.s1.gov (415) 422-0758 UUCP: ...!ucbvax!decwrl!mordor!jdb ...!seismo!mordor!jdb