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 cur
rent map" request to the local ypserv.
If run interactively, ypxfr writes it's 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 rea
sonable 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.
The following options are supported:
-f Force a map transfer. Normally, ypxfr will not
transfer a map if it determines that the NIS mas
ter'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 master is. If host is not specified,
ypxfr asks the NIS service for the name of the mas
ter, 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 diretory 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)
Thorsten Kukuk <kukuk@suse.de>
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