The
utility distributes updated NIS databases (or
maps
from an NIS master server to NIS slave servers within an NIS
domain.
It is normally only run on the NIS master by
/var/yp/Makefile
whenever any of the NIS maps are updated.
Note that
/var/yp/Makefile
does not invoke
by default: the
``NOPUSH=True
''
entry in the Makefile must first be commented out
(the default
Fx configuration assumes a small network with only
a single NIS server; in such a configuration,
is not needed).
By default,
determines the names of the slave servers for a domain by searching the
ypservers
map.
A destination host (or a list of hosts) can also be manually
specified on the command line.
Once it has a complete list of slave servers, it sends a 'map transfer'
request to each slave, which in turn reads a copy of the map from
the master NIS server using
ypxfr(8).
Included within each request is the name of the map to be copied
and some special information required by
ypxfr(8)
to successfully 'callback' to
and carry out the transfer.
Any error messages
receives from
ypxfr(8)
via callback will be printed to stderr.
The following options are available:
-d domain
Specify a particular domain.
The NIS domain of
the local host system is used by default.
If the local host's domain
name is not set, the domain name must be specified with this flag.
-t timeout
Specify a timeout value in seconds.
This timeout
controls how long
will wait for a response from a slave server before sending a
map transfer request to the next slave server in its list.
-j #parallel jobs
The
utility normally performs transfers serially, meaning that it will
send a map transfer request to one slave server and then wait for
it to respond before moving on to the next slave server.
#include <environments>
with many slaves, it is more efficient to initiate several map transfers
at once so that the transfers can take place in parallel.
The
-j
flag is used to specify the desired number of parallel jobs:
will initiate the specified number of transfers immediately and
listen for responses.
If the number of specified parallel jobs is
less than the number of slave servers,
will initiate only the number of specified jobs and then wait
for some of them to finish before starting any more.
Note that
handles callbacks asynchronously, which means that it will collect
and display the callback information received from
ypxfr(8)
as soon as it arrives, even it arrives before all of the map
transfer requests have been sent.
-h host
Can be used to transfer a map to a user-specified machine or
group of machines instead of the list of servers contained in
the
ypservers
map.
A list of hosts can be specified by using multiple
instances of the
-h
flag.
-p path
By default,
expects all the local NIS maps to be stored under
/var/yp
The
-p
flag can be used to specify an alternate path in the event that
the system administrator decides to store the NIS maps somewhere else.
-v
Verbose mode: it causes
to print debugging messages as it runs.
Specifying this flag twice
makes
even more verbose.
FILES
/var/yp/[domainname]/ypservers
the NIS ypservers map containing the names of all servers in
a particular NIS domain
The mechanism for transferring NIS maps in NIS v1 is different
than that in NIS version 2.
This version of
has support for transferring maps to NIS v2 systems only.
