Ubuntu Manpage: xnbd-register - Restore xNBD sessions upon boot

NAME

       xnbd-register - Restore xNBD sessions upon boot

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