'\" t
.\"     Title: ypxfr
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 12/31/2020
.\"    Manual: NIS Reference Manual
.\"    Source: NIS Reference Manual
.\"  Language: English
.\"
.TH "YPXFR" "8" "12/31/2020" "NIS Reference Manual" "NIS Reference Manual"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
ypxfr \- transfer NIS database from remote server to local host
.SH "SYNOPSIS"
.HP \w'\fB/usr/lib/yp/ypxfr\fR\ 'u
\fB/usr/lib/yp/ypxfr\fR [\-f] [\-c] [\-d\ \fItarget\fR\ \fIdomain\fR] [\-h\ \fIsource\fR\ \fIhost\fR] [\-s\ \fIsource\fR\ \fIdomain\fR] [\-C\ \fItaskid\fR\ \fIprogram\-number\fR\ \fIhost\fR\ \fIport\fR] [\-p\ \fIyp_path\fR] \fImapname\fR...
.br

.SH "DESCRIPTION"
.PP
\fBypxfr\fR
copies an NIS database from one NIS server to the local host by using the NIS service\&.
\fBypxfr\fR
is generally invoked by
\fBypinit\fR
or by
\fBypserv,\fR
when
\fBypserv\fR
receives a map transfer request from
\fByppush\&.\fR
It creates a temporary map in the directory
/var/yp/domain
(this directory must already exist;
\fIdomain\fR
is the default domainname for the local host), fills it by getting the map\*(Aqs 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,
\fBypxfr\fR
will attempt to send a "clear current map" request to the local
\fBypserv\&.\fR
.PP
If run interactively,
\fBypxfr\fR
writes its output to stderr\&. However, if it is invoked without a controlling terminal, it will log the output to syslog\&.
.PP
\fBypxfr\fR
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\&.
.PP
In order to maintain consistency across all NIS servers,
\fBypxfr\fR
can be run periodically in a
\fBcron\fR
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
\fIpasswd\&.byname\fR
and
\fIpasswd\&.byuid )\fR
should be updated perhaps once every hour\&. Examples are in
/usr/lib/yp: ypxfr_1perday, ypxfr_2perday,
and
\fBypxfr_1perhour\&.\fR
They can serve as reasonable first cuts\&.
.PP
Normally all updates should be propagated by
\fByppush\fR
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\&.
.SH "OPTIONS"
.PP
The following options are supported:
.PP
\fB\-f\fR
.RS 4
Force a map transfer\&. Normally,
\fBypxfr\fR
will not transfer a map if it determines that the NIS master\*(Aqs copy is not newer than the existing copy already on the local host\&. This flag forces a transfer regardless of which server\*(Aqs version is more recent\&.
.RE
.PP
\fB\-c\fR
.RS 4
Do not send a "clear current map" request to the
\fBypserv\fR
process running on the local host\&. This flag is normally used when invoking
\fBypxfr\fR
by
\fBypinit\fR
or if
\fBypserv\fR
is not running locally at the time you are running
\fBypxfr\&.\fR
Otherwise,
\fBypxfr\fR
will complain that it cannot talk to the local
\fBypserv,\fR
and the transfer will fail\&.
.RE
.PP
\fB\-d\fR\fI domain\fR
.RS 4
Specify a domain other than the default NIS domain\&.
.RE
.PP
\fB\-h\fR\fI source host\fR
.RS 4
Get the map from
\fIhost\fR, regardless of what the map says the master is\&. If
\fIhost\fR
is not specified,
\fBypxfr\fR
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\&.
.RE
.PP
\fB\-s\fR\fI source domain\fR
.RS 4
Specify a source domain from which to transfer a map that should be the same across domains\&.
.RE
.PP
\fB\-C\fR\fI taskid progam\-number host port\fR
.RS 4
This option is
\fBonly\fR
for use by
\fBypserv \&.\fR
When
\fBypserv\fR
invokes
\fBypxfr\fR, it specifies that
\fBypxfr\fR
should call back a
\fByppush\fR
process at the host with
IP
address or name
\fIhost\fR, registered as program number
\fIprogam\-number\fR, listening on port
\fIport\fR, and waiting for a response to transaction
\fItaskid\fR\&.
.RE
.PP
\fB\-p\fR\fI yp_path\fR
.RS 4
Change the directory for the maps to
\fIyp_path/[domainname]/\fR, the default is
/var/yp/[domainname]\&.
.RE
.PP
\fImapname\fR
.RS 4
One or more names of the map to transfer\&.
.RE
.SH "FILES"
.PP
/var/yp/[domainname]/[maps]
.SH "SEE ALSO"
.PP
\fBypserv\fR(8),
\fByppush\fR(8),
\fBypinit\fR(8),
\fBcron\fR(8),
\fBcrontab\fR(5)
.SH "AUTHOR"
.PP
Thorsten Kukuk <kukuk@linux\-nis\&.org>