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ypxfr(8)							     ypxfr(8)



NAME

  ypxfr	- Transfer a Network Information Service (NIS) map from	a NIS server
  to the local host

SYNOPSIS

  /var/yp/ypxfr	[-a method] -f	[-h host] -d [domain] [-c] [-C tid prog	ipadd
  port]	mapname

OPTIONS

  -a method
      Specifies	that NIS maps are to be	stored in one of the following for-
      mats:

      b	  btree	-- Recommended when creating and maintaining very large	maps.

      d	  dbm/ndbm -- For backward compatibility.  This	is the default.

      h	  hash -- A potentially	quicker	method for managing small maps.

  -f  Force the	transfer to occur even if the version at the MASTER is not
      more recent than the local version.

  -c  Do not send a "Clear current map"	request	to the local ypserv process.
      This option should be used if ypserv is not running locally at the time
      when ypxfr is running. Otherwise,	ypxfr will report that it can not
      talk to the local	ypserv,	and the	transfer will fail.

  -h host
      Get the map from host, regardless	of which map is	the master.  If	host
      is not specified,	ypxfr will ask the NIS service for the name of the
      master, and try to get the map from there.  The host option can be a
      name or an IP address in dotted numeric notation.

  -d domain
      Specify a	domain other than the default domain.

  -C tid prog ipadd port
      This option is only for use by ypserv.  When ypserv invokes ypxfr, it
      specifies	that ypxfr should call back a yppush process at	the host with
      IP address ipaddr, registered as program number prog, listening on port
      port, and	waiting	for a response to transaction tid.

DESCRIPTION

  The ypxfr command moves a NIS	map, specified by the mapname  argument, to
  the local host by making use of normal NIS services.	It creates a tem-
  porary map in	the directory /var/yp/domain (which must already exist),
  fills	it by enumerating the map's entries, obtains the map parameters	(mas-
  ter and order	number)	and loads them into the	map. Once ypxfr	has accom-
  plished these	tasks, it deletes any old versions of the map and moves	the
  temporary map	to the real mapname.

  If ypxfr is run interactively, it writes its output to the terminal. How-
  ever,	if it is invoked without a controlling terminal, and if	the log	file
  /var/cluster/members/{memb}/yp/ypxfr.log exists, it appends all its output
  to that file.	 Since ypxfr is	most often run from
  /var/spool/cron/crontab/root,	or by ypserv, you can use the log file to
  retain a record of what was attempted, and the results.

  For consistency between servers, ypxfr should	be run periodically for	every
  map in the NIS database. Different maps change at different rates:  the
  services.byname map may not change for months	at a time, for instance, and
  may therefore	be checked only	once a day. It is possible that	mail.aliases
  or hosts.byname changes several times	per day.  In such a case, it is
  appropriate to check hourly for updates. A cron(8) entry should be used to
  perform periodic updates automatically on NIS	server machines	only.  Rather
  than having a	separate cron entry for	each map, commands can be grouped to
  update several maps in a shell script.  Examples (mnemonically named)	are
  in /var/yp: ypxfr_1perday, ypxfr_2perday, and	ypxfr_1perhour.	They can
  serve	as models for you to use.

  See ypfiles(4) and ypserv(8) for an overview of NIS.

RESTRICTIONS

  You must use the same	database format	for each map in	a domain. In addi-
  tion,	a server serving multiple NIS domains must use the same	database for-
  mat for all domains.

  Although a Tru64 UNIX	NIS server that	takes advantage	of btree files will
  be able to store very	large maps, NIS	slave servers that lack	this feature
  might	have a much smaller limit on the number	of map entries they can	han-
  dle.	It may not be possible to distribute very large	maps from a Tru64
  UNIX NIS master server to a slave server that	lacks support for very large
  maps.	 NIS clients are not affected by these enhancements.

EXAMPLES

  The following	is an example of the ypxfr command used	with the btree data-
  base routine to store	NIS maps.

       ypxfr -a	b group.byname

FILES

  /var/cluster/members/{memb}/yp/ypxfr.log
      The ypxfr	log file. Each cluster member has its own copy.

  /var/yp/ypxfr_1perday
      Script to	transfer maps once a day.

  /var/yp/ypxfr_2perday
      Script to	transfer maps twice a day.

  /var/yp/ypxfr_1perhour
      Script to	transfer maps once an hour.

  /var/spool/cron/crontab/root
      The crontab script.








SEE ALSO

  Commands: cron(8), yppush(8),	ypserv(8), ypsetup(8)


  Functions: btree(3), dbm(3), dbopen(3), hash(3), ndbm(3)

  Files: ypfiles(4)