---
name: "xnbd-wrapper"
section: "8"
platform: "linux"
package: "xnbd-server"
version: "0.3.0-3"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/xnbd-wrapper"
---

# xnbd-wrapper(8)

Manage multiple files to be exported as a block device to other computers running the GNU/Linux(tm) Operating System

## NAME

xnbd-wrapper - Manage multiple files to be exported as a block device to other computers running the GNU/Linux(tm) Operating System

## SYNOPSIS

**xnbd-wrapper** \[ --imgfile *IMAGE* \[--imgfile *IMAGE* ...\] \] \[--laddr *ADDRESS*\] \[--lport *PORT*\] \[--socket *PATH*\] \[--xnbd-server *PATH*\] \[--daemonize\] \[--logpath *PATH*\] \[--max-buf-size *NUMBER*\] \[--max-queue-size *NUMBER*\]

## DESCRIPTION

**xnbd-wrapper** is a super-server for xnbd-server. Its purpose is to manage multiple exported images at once. A client may connect to this super-server and it will be indirected to the actual xnbd-server providing the requested resource.

**xnbd-wrapper** comes handy if you want to export multiple files (or block devices) on a single host. Instead of starting multiple xnbd-server instances and remember the exported port for each, you can use **xnbd-wrapper** to looks up the requested image file name and map it automatically to the corresponding xnbd-server.

## OPTIONS

The following options are supported:

- **--daemonize**

  Go into background as soon as the xnbd-server is started up

- **--imgfile** *IMAGE*

  Export the image file *IMAGE* through **xnbd-wrapper**, with *IMAGE* being a block device or a file name of an image file.

  **xnbd-wrapper** will export the file name accessible through this name to clients, which may connect to the server by providing this name

  This option can be specified multiple times. In this case, xnbd-wrapper will export all *IMAGE* files at once. Alternatively, this argument can be omitted and images may be (un-)exported ar runtime with xnbd-wrapper-ctl.

- **--laddr** *ADDRESS*

  The address, where this wrapper shall listen for incoming connections. You can specify any resolvable hostname or IP address, being in IPv4 or IPv6 notation.

- **--logpath** *FILE*

  Log informational messages to file *FILE* rather than stderr/syslog.

- **--syslog**

  Log informational messages to syslog.

- **--lport** *PORT*

  Accept incoming connections on the given *PORT*. A valid port is any number between 1 and 65536. You may not use the same listeing port more than once per system. If this argument is not given, xNBD will listen on port 8520 by default.

(**--port** *PORT*)

Deprecated, please use **--lport** instead. This option might be removed in future releases.

- **--socket** *PATH*

  The xNBD wrapper can be controlled through a control socket. When given, use *PATH* as file name, default is /var/run/xnbd-wrapper.ctl.

- **--xnbd-bgctl** *COMMAND*

  Specifies the path to the xnbd-bgctl executable. *COMMAND* can be a file name or a command to resolve to a file name using $PATH. By default, "xnbd-bgctl" resolved from $PATH is used.

- **--xnbd-server** *COMMAND*

  Specifies the path to the xnbd-server executable. The wrapper will spawn server instances on demand. *COMMAND* can be a file name or a command to resolve to a file name using $PATH. By default, "xnbd-server" resolved from $PATH is used.

(**--xnbd-binary** *PATH*)

Deprecated, please use **--xnbd-server** *PATH* instead. This option might be removed in future releases.

- **--cow**

  Invoke [xnbd-server(8)](/xnbd-server/8.md) instances using parameter --cow-target.

- **--readonly**

  Invoke [xnbd-server(8)](/xnbd-server/8.md) instances using parameter --readonly.

- **--max-queue-size** *NUMBER*

  Parameter forwarded to proxy mode xnbd-server on invocation. See **[xnbd-server(8)](/xnbd-server/8.md)** for details, please.

- **--max-buf-size** *NUMBER*

  Parameter forwarded to proxy mode xnbd-server on invocation. See **[xnbd-server(8)](/xnbd-server/8.md)** for details, please.

## SEE ALSO

[xnbd-client(1)](/xnbd-client/1.md), [xnbd-server(8)](/xnbd-server/8.md), [xnbd-wrapper-ctl(8)](/xnbd-wrapper-ctl/8.md)

## AUTHOR

The NBD kernel module and the NBD tools have been written by Pavel Macheck (pavel@ucw.cz) and is now maintained by Paul Clements (Paul.Clements@steeleye.com).

The xNBD userland programs have been written by Takahiro Hirofuchi (t.hirofuchi@aist.go.jp).

This manual page was written by Arno Toell (arno@debian.org) for the Debian GNU/Linux system (but may be used by others). Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, version 2, as published by the Free Software Foundation.