YPSERV(8)																 YPSERV(8)

NAME

       ypxfr - transfer NIS database from remote server to local host

SYNOPSIS

       /usr/lib/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/lib/yp: ypxfr_1perday, ypxfr_2perday,  and  ypxfr_1per-
       hour.  They can serve as reasonable first cuts.

       Normally all updates should be propagated by yppush when /var/yp/Makefile 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 complain  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 master 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 mas-
	      ter 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)