1YPXFR(8) NIS Reference Manual YPXFR(8)
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6 ypxfr - transfer NIS database from remote server to local host
7
9 /usr/lib/yp/ypxfr [-f] [-c] [-d target domain] [-h source host]
10 [-s source domain]
11 [-C taskid program-number host port] [-p yp_path]
12 mapname...
13
16 ypxfr copies an NIS database from one NIS server to the local host by
17 using the NIS service. ypxfr is generally invoked by ypinit or by
18 ypserv, when ypserv receives a map transfer request from yppush. It
19 creates a temporary map in the directory /var/yp/domain (this directory
20 must already exist; domain is the default domainname for the local
21 host), fills it by getting the map's entries and fetches the map
22 parameters (master and order number). If the transfer was successful,
23 the old version of the map will be deleted and the temporary copy will
24 be moved into its place. Then, ypxfr will attempt to send a "clear
25 current map" request to the local ypserv.
26 If run interactively, ypxfr writes its output to stderr. However, if it
28 is invoked without a controlling terminal, it will log the output to
29 syslog.
30 ypxfr is used primarily in environments where several NIS servers are
32 in use. For all maps, you have a NIS master server, which maintains a
33 canonical copy of the NIS map, and all the other servers, the NIS
34 slaves, copy the new version of the map from the master whenever a
35 update was made. Normally, you have one NIS master for all maps.
36 In order to maintain consistency across all NIS servers, ypxfr can be
38 run periodically in a cron job. Maps which change infrequently need
39 only be updated once a day (preferably late at night when system usage
40 is lowest), where those with frequent changes (such as passwd.byname
41 and passwd.byuid ) should be updated perhaps once every hour. Examples
42 are in /usr/lib/yp: ypxfr_1perday, ypxfr_2perday, and ypxfr_1perhour.
43 They can serve as reasonable first cuts.
44 Normally all updates should be propagated by yppush when
46 /var/yp/Makefile is run on the NIS master server, however it is a good
47 practice on large networks where possible outages could cause NIS
48 slaves to fall out of sync with the master.
49
51 The following options are supported:
52 -f
54 Force a map transfer. Normally, ypxfr will not transfer a map if it
55 determines that the NIS master's copy is not newer than the
56 existing copy already on the local host. This flag forces a
57 transfer regardless of which server's version is more recent.
58 -c
60 Do not send a "clear current map" request to the ypserv process
61 running on the local host. This flag is normally used when invoking
62 ypxfr by ypinit or if ypserv is not running locally at the time you
63 are running ypxfr. Otherwise, ypxfr will complain that it cannot
64 talk to the local ypserv, and the transfer will fail.
65 -d domain
67 Specify a domain other than the default NIS domain.
68 -h source host
70 Get the map from host, regardless of what the map says the master
71 is. If host is not specified, ypxfr asks the NIS service for the
72 name of the master, and tries to get the map from there. This
73 option is used to insure that ypxfr only copies maps from the NIS
74 master server.
75 -s source domain
77 Specify a source domain from which to transfer a map that should be
78 the same across domains.
79 -C taskid progam-number host port
81 This option is only for use by ypserv . When ypserv invokes ypxfr,
82 it specifies that ypxfr should call back a yppush process at the
83 host with IP address or name host, registered as program number
84 progam-number, listening on port port, and waiting for a response
85 to transaction taskid.
86 -p yp_path
88 Change the directory for the maps to yp_path/[domainname]/, the
89 default is /var/yp/[domainname].
90 mapname
92 One or more names of the map to transfer.
93
95 /var/yp/[domainname]/[maps]
96
98 ypserv(8), yppush(8), ypinit(8), cron(8), crontab(5)
99
101 Thorsten Kukuk <kukuk@linux-nis.org>
102NIS Reference Manual 11/12/2021 YPXFR(8)