SYNOPSIS

xnbd-register [OPTIONS] --start

xnbd-register [OPTIONS] --stop

xnbd-register [OPTIONS] --restart

xnbd-register [OPTIONS] --status

DESCRIPTION

With the xnbd-register command one can restore xnbd-wrapper and xnbd-client sessions based on a configuration file. This is useful to start client, wrapper or both upon boot.

To achieve this, xnbd-register reads a semi-structured configuration file located in /etc/xnbd.conf. See below for format hints.

OPTIONS

The following options are supported:

--start

Start devices configured in the configuration files. If the configuration files describes volumes, xnbd-register will try to establish a client connection to the configured wrapper instance.

Alternatively, xnbd-register will start sharing configured volumes by starting an xnbd-wrapper super server.

--status

Retrieve wrapper status from a running xnbd-wrapper command, if applicable.

--stop

Analogous to the start option, the stop argument will stop all xnbd connection, being client or wrapper instances.

--restart

Restart all xnbd instances, being client or wrapper

--config FILE

Config file to use. Defaults to /etc/xnbd.conf.

--quiet

Do not produce verbose output

CONFIGURATION FILE

xnbd-register will read its defaults from /etc/xnbd.conf. This is a semi-structured configuration file, describing client and wrapper connections that are supposed to be restored upon start of the system.

The syntax of the file is a JSON data structure, allowing comments starting with a hash key ("#"). Two types of objects are recognized: xnbd volumes and a wrapper instance. xnbd volumes are indexed by the supposed devices name. This is, to restore /dev/nbd0 an object named "nbd0" must be configured. Valid arguments are host, name and port. So, for example, this is to configure /dev/nbd0 connecting to localhost on port 8520. If present, identify the shared device by the configured logical name:

"nbd0": {
    "host": "127.0.0.1",
    "port": 8520,
    "name": "name"
}

Similarly, a wrapper instance configures an xnbd-wrapper. Valid options are:

address

Specifies the listening address

port

Specifies the listening port

socket

Specifies the listening socket for the control channels

logpath

Specifies the log path where logging output is being redirected to

volumes

A mapping of volumes which are exported. Mapping keys are export names, mapping values are disk image paths.

"wrapper": {
    "address": "127.0.0.1",
    "port": 8520,
    "socket": "/var/run/xnbd.ctl",
    "logpath": "/var/log/xnbd.log",
    "volumes": {
        "one": "/dev/volume",
        "two": "/dev/sdb1",
        "three": "/var/lib/image.file",
    }
}

AUTHOR

xnbd-register was written by Arno Toell ([email protected]) for the Debian GNU/Linux system.

This manual page was written by Arno Toell ([email protected]) 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.