Provided by: nbdkit_1.1.3-2_amd64 
NAME
nbdkit - A toolkit for creating NBD servers
SYNOPSIS
nbdkit [-f] [-g GROUP] [-i IPADDR] [-P PIDFILE] [-p PORT]
[-r] [-s] [-U SOCKET] [-u USER] [-v] [-V]
PLUGIN.so [key=value [key=value [...]]]
DESCRIPTION
"nbdkit" is both a toolkit for creating Network Block Device (NBD) servers from
"unconventional" sources and the name of an NBD server.
To create a new block device source, all you have to do is write a few glue functions.
The liberal licensing of nbdkit is meant to allow you to link nbdkit with proprietary
libraries or include nbdkit in proprietary code.
If you want to write an nbdkit plugin, you should read nbdkit-plugin(3).
Several plugins may be found in "LIBDIR/nbdkit/plugins" where "LIBDIR" is set at compile
time and might be a path such as "/usr/lib", "/usr/lib64" or "/usr/local/lib".
EXAMPLES
Serve file "disk.img" on port 10809:
nbdkit .../plugins/nbdkit-file-plugin.so file=disk.img
Run the example1 plugin and connect to it using guestfish(1):
nbdkit .../plugins/nbdkit-example1-plugin.so
guestfish --ro -a nbd://localhost
Run the example3 plugin and connect to it using guestfish(1):
nbdkit .../plugins/nbdkit-example3-plugin.so size=1G
guestfish --ro -a nbd://localhost
To display usage information about a specific plugin:
nbdkit --help .../plugins/nbdkit-example1-plugin.so
GLOBAL OPTIONS
--help
Display brief command line usage information and exit.
-f
--foreground
--no-fork
Don't fork into the background.
-g GROUP
--group GROUP
Change group to "GROUP" after starting up. A group name or numeric group ID can be
used.
The server needs sufficient permissions to be able to do this. Normally this would
mean starting the server up as root.
See also -u.
-i IPADDR
--ip-addr IPADDR
--ipaddr IPADDR
Listen on the specified interface. The default is to listen on all interfaces. See
also -p.
-P PIDFILE
--pid-file PIDFILE
--pidfile PIDFILE
Write "PIDFILE" (containing the process ID of the server) after nbdkit becomes ready
to accept connections.
If the file already exists, it is overwritten. nbdkit does not delete the file when
it exits.
-p PORT
--port PORT
Change the TCP/IP port number on which nbdkit serves requests. The default is 10809.
See also -i.
-r
--read-only
--readonly
The export will be read-only. If a client writes, then it will get an error.
Note that some plugins inherently don't support writes. With those plugins the -r
option is added implicitly.
Copy-on-write (or "snapshot") functionality is not supported by this server. However
if you are using qemu as a client (or indirectly via libguestfs) then it supports
snapshots.
-s
--single
--stdin
Don't fork. Handle a single NBD connection on stdin/stdout. After stdin closes, the
server exits.
You can use this option to run nbdkit from inetd, systemd or similar superservers; or
just for testing; or if you want to run nbdkit in a non-conventional way.
This option implies --foreground.
-U SOCKET
--unix SOCKET
Accept connections on the Unix domain socket "SOCKET" (which is a path).
nbdkit neither creates nor deletes this socket. You should create the socket and set
the desired permissions and ownership before running the server.
-u USER
--user USER
Change user to "USER" after starting up. A user name or numeric user ID can be used.
The server needs sufficient permissions to be able to do this. Normally this would
mean starting the server up as root.
See also -g.
-v
--verbose
Enable verbose messages.
It's a good idea to use -f as well so the process does not fork into the background
(but not required).
-V
--version
Print the version number of nbdkit and exit.
PLUGIN CONFIGURATION
After specifying the plugin name you can (optionally, it depends on the plugin) give
plugin configuration on the command line in the form of "key=value". For example:
nbdkit .../plugins/nbdkit-file-plugin.so file=disk.img
To list all the options supported by a plugin, do:
nbdkit --help .../plugins/nbdkit-file-plugin.so
SEE ALSO
nbdkit-plugin(3), nbdkit-example1-plugin(1), nbdkit-example2-plugin(1),
nbdkit-example3-plugin(1), nbdkit-file-plugin(1), nbdkit-gzip-plugin(1),
nbdkit-libvirt-plugin(1), nbdkit-vddk-plugin(1). nbdkit-xz-plugin(1).
AUTHORS
Richard W.M. Jones
COPYRIGHT
Copyright (C) 2013 Red Hat Inc.
LICENSE
Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:
• Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.
• Neither the name of Red Hat nor the names of its contributors may be used to endorse
or promote products derived from this software without specific prior written
permission.
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