1 <!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [
3 <!-- Process this file with docbook-to-man to generate an nroff manual
4 page: `docbook-to-man manpage.sgml > manpage.1'. You may view
5 the manual page with: `docbook-to-man manpage.sgml | nroff -man |
6 less'. A typical entry in a Makefile or Makefile.am is:
8 manpage.1: manpage.sgml
12 <!-- Fill in your name for FIRSTNAME and SURNAME. -->
13 <!ENTITY dhfirstname "<firstname>Wouter</firstname>">
14 <!ENTITY dhsurname "<surname>Verhelst</surname>">
15 <!-- Please adjust the date whenever revising the manpage. -->
16 <!ENTITY dhdate "<date>$Date$</date>">
17 <!-- SECTION should be 1-8, maybe w/ subsection other parameters are
18 allowed: see man(7), man(1). -->
19 <!ENTITY dhsection "<manvolnum>8</manvolnum>">
20 <!ENTITY dhemail "<email>wouter@debian.org</email>">
21 <!ENTITY dhusername "Wouter Verhelst">
22 <!ENTITY dhucpackage "<refentrytitle>NBD-CLIENT</refentrytitle>">
23 <!ENTITY dhpackage "nbd-client">
25 <!ENTITY debian "<productname>Debian GNU/Linux</productname>">
26 <!ENTITY gnu "<acronym>GNU</acronym>">
40 <holder>&dhusername;</holder>
50 <refname>&dhpackage;</refname>
52 <refpurpose>connect to a server running nbd-server(1), to use its
53 exported block device</refpurpose>
57 <command>&dhpackage;</command>
58 <arg><option>bs=<replaceable>blocksize</replaceable></option></arg>
59 <arg><option>timeout=<replaceable>seconds</replaceable></option></arg>
60 <arg choice=plain><option><replaceable>host</replaceable></option></arg>
61 <arg choice=plain><option><replaceable>port</replaceable></option></arg>
62 <arg choice=plain><option><replaceable>nbd-device</replaceable></option></arg>
63 <arg><option>-sdp</option></arg>
64 <arg><option>-swap</option></arg>
65 <arg><option>-persist</option></arg>
66 <arg><option>-nofork</option></arg>
69 <command>&dhpackage;</command>
70 <arg choice=plain><option>-d <replaceable>nbd-device</replaceable></option></arg>
73 <command>&dhpackage;</command>
74 <arg choice="plain"><option>-c <replaceable>nbd-device</replaceable></option></arg>
78 <title>DESCRIPTION</title>
80 <para>With <command>&dhpackage;</command>, you can connect to a
81 server running <command>nbd-server</command>, thus using raw
82 diskspace from that server as a blockdevice on the local
85 <para>To do this, support from the Linux Kernel is necessary, in
86 the form of the Network Block Device (NBD). When you have that,
87 either in the kernel, or as a module, you can connect to an NBD
88 server and use its exported file through a block special file with
93 <title>OPTIONS</title>
95 <para>The following options are supported:</para>
99 <term><option>bs=<replaceable>blocksize</replaceable></option></term>
101 <para>Use a blocksize of "blocksize". Default is 1024;
102 allowed values are either 512, 1024, 2048 or 4096</para>
106 <term><option>host</option></term>
108 <para>The hostname of the machine running
109 <command>nbd-server</command>.</para>
113 <term><option>timeout=<replaceable>seconds</replaceable></option></term>
115 <para>Set the connection timeout to "seconds". For this to
116 work, you need a kernel with support for the NBD_SET_TIMEOUT
117 ioctl; this was introduced into Linus' tree on 2007-10-11,
118 and will be part of kernel 2.6.24.</para>
122 <term><option>port</option></term>
124 <para>The TCP port on which <command>nbd-server</command> is
125 running at the server.</para>
129 <term><option>nbd-device</option></term>
131 <para>The block special file this nbd-client should connect
138 <para>Check whether the specified nbd device is
140 <para>If the device is connected, &dhpackage; will exit
141 with an exit state of 0 and print the PID of the &dhpackage;
142 instance that connected it to stdout.
143 <para>If the device is not
144 connected or does not exist (for example because the nbd
145 module was not loaded), &dhpackage; will exit with an exit
146 state of 1 and not print anything on stdout.</para>
147 <para>If an error occurred, &dhpackage; will exit with an exit
148 state of 2, and not print anything on stdout either.</para>
154 <para>Disconnect the specified nbd device from the
159 <term>-persist</term>
161 <para>When this option is specified, &dhpackage; will
162 immediately try to reconnect an nbd device if the
163 connection ever drops unexpectedly due to a lost
164 server or something similar.</para>
168 <term><option>-sdp</option></term>
170 <para>Connect to the server using the Socket Direct Protocol
171 (SDP), rather than IP. See nbd-server(1) for details.
176 <term><option>-swap</option></term>
178 <para>Specifies that this NBD device will be used as
179 swapspace. If you intend to do that, please use this
180 option to prevent deadlocks. You'll need a special kernel
181 patch, available at NBD's homepage:
182 http://atrey.karlin.mff.cuni.cz/~pavel</para>
186 <term><option>-nofork</option></term>
188 <para>Specifies that the NBD client should not detach and
189 daemonize itself. This is mostly useful for debugging.</para>
194 <title>EXAMPLES</title>
196 <para>Some examples of nbd-client usage:</para>
197 <itemizedlist mark="none">
199 <para>To connect to a server running on port 2000 at host
200 "server.domain.com", using the client's block special file
202 <para><command>nbd-client server.domain.com 2000
203 /dev/nb0</command></para>
206 <para>To connect to a server running on port 2001 at host
207 "swapserver.domain.com", using the client's block special
208 file "/dev/nb1", for swap purposes:</para>
209 <para><command>nbd-client swapserver.domain.com 2001 /dev/nb1
210 -swap</command></para>
213 <para>To disconnect the above connection again (after making
214 sure the block special file is not in use anymore):</para>
215 <para><command>nbd-client -d /dev/nb1</command></para>
220 <title>SEE ALSO</title>
222 <para>nbd-server (1).</para>
226 <title>AUTHOR</title>
227 <para>The NBD kernel module and the NBD tools have been written by
228 Pavel Macheck (pavel@ucw.cz).</para>
230 <para>The kernel module is now maintained by Paul Clements
231 (Paul.Clements@steeleye.com), while the userland tools are maintained by
232 Wouter Verhelst (wouter@debian.org)</para>
234 <para>This manual page was written by &dhusername; (&dhemail;) for
235 the &debian; system (but may be used by others). Permission is
236 granted to copy, distribute and/or modify this document under the
237 terms of the <acronym>GNU</acronym> General Public License,
238 version 2, as published by the Free Software Foundation.</para>
243 <!-- Keep this comment at the end of the file
248 sgml-minimize-attributes:nil
249 sgml-always-quote-attributes:t
252 sgml-parent-document:nil
253 sgml-default-dtd-file:nil
254 sgml-exposed-tags:nil
255 sgml-local-catalogs:nil
256 sgml-local-ecat-files:nil