YPSERV(8)							     YPSERV(8)



NAME
       ypxfr - transfer NIS database from remote server to local host

SYNOPSIS
       /usr/lib64/yp/ypxfr [ -f ] [ -c ] [ -d target domain ]
	    [ -h source host ] [ -s source domain ]
	    [ -C taskid program-number ipaddr port ]
	    [ -p yp_path ] mapname ...


DESCRIPTION
       ypxfr  copies  an NIS database from one NIS server to the local host by
       using the NIS service.  ypxfr is generally  invoked  by	ypinit	or  by
       ypserv,	when  ypserv  receives a map transfer request from yppush.  It
       creates a temporary map in the directory /var/yp/domain	(this	direc-
       tory   must  already   exist;  domain is the default domainname for the
       local host), fills it by getting the map's entries and fetches the  map
       parameters  (master and order number).  If the transfer was successful,
       the old version of the map will be deleted and the temporary copy  will
       be  moved  into	its  place.  Then, ypxfr will attempt to send a "clear
       current map" request to the local ypserv.

       If  run interactively, ypxfr writes its output to stderr.  However,  if
       it is invoked without a controlling terminal, it will log the output to
       syslog.

       ypxfr is used primarily in environments where several NIS  servers  are
       in use.	For all maps, you have a NIS master server, which  maintains a
       canonical copy of the NIS map, and  all	the  other  servers,  the  NIS
       slaves,	copy  the  new	version	 of the map from the master whenever a
       update was made.	 Normally, you have one NIS master for all maps.

       In order to maintain consistency across all NIS servers, ypxfr  can  be
       run  periodically  in  a	 cron job. Maps which change infrequently need
       only be updated once a day (preferably late at night when system	 usage
       is  lowest),  where  those with frequent changes (such as passwd.byname
       and passwd.byuid ) should be updated perhaps once every hour.  Examples
       are in /usr/lib64/yp: ypxfr_1perday, ypxfr_2perday, and ypxfr_1perhour.
       They can serve as reasonable first cuts.

       Normally all updates should be propagated by yppush when	 /var/yp/Make-
       file  is run on the NIS master server, however it is a good practice on
       large networks where possible outages could cause NIS  slaves  to  fall
       out of sync with the master.



OPTIONS
       The following options are supported:

       -f     Force a map transfer. Normally, ypxfr will not transfer a map if
	      it determines that the NIS master's copy is not newer  than  the
	      existing	copy  already  on  the	local host. This flag forces a
	      transfer regardless of which server's version is more recent.

       -c     Do not send a "clear current map" request to the ypserv  process
	      running  on  the	local  host.  This  flag is normally used when
	      invoking ypxfr by ypinit or if ypserv is not   running   locally
	      at   the time you are running ypxfr.  Otherwise, ypxfr will com-
	      plain that it cannot talk to the local ypserv, and the  transfer
	      will fail.

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

       -h source host
	      Get  the map from host, regardless of what the map says the mas-
	      ter is.  If host is not specified, ypxfr asks  the  NIS  service
	      for the name of the master, and tries to get the map from there.
	      This option is used to insure that ypxfr only copies  maps  from
	      the NIS master server.

       -s source domain
	      Specify a source domain from which to transfer a map that should
	      be the same across domains.

       -C taskid progam-number ipaddr 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
	      progam-number,  listening	 on  port  port,  and  waiting	for  a
	      response to transaction taskid.

       -p yp_path
	      Change the directory for the maps to yp_path/[domainname]/,  the
	      default is /var/yp/[domainname].

       mapname
	      One or more names of the map to transfer.

FILES
       /var/yp/[domainname]/[maps]

SEE ALSO
       ypserv(8), yppush(8), ypinit(8), cron(8), crontab(5)

AUTHOR
       Thorsten Kukuk <kukuk@suse.de>



YP Server			  August 2001			     YPSERV(8)