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ypxfr(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
   directory   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_1perhour.
   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 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>



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