nbdkit-random-plugin(1)

NAME
nbdkit-random-plugin - plugin to serve random data

SYNOPSIS
 nbdkit random [size=]SIZE [seed=SEED] [fast=true]

DESCRIPTION
"nbdkit-random-plugin" is a plugin for nbdkit(1) which serves random data. This plugin is mainly good for testing NBD clients. This plugin creates a non-sparse random disk, for a sparse random disk see nbdkit-sparse-random-plugin(1). For a plugin containing a predictable test pattern see nbdkit-pattern-plugin(1).

The size of the virtual disk must be specified using the "size" parameter. If you specify the "seed" parameter then you will get the same random data over multiple runs with the same seed.

In "fast=true" mode, the same sector of random data is repeated across the disk with small variations. As the name suggests, this is much faster, and is usually sufficient for testing.

The random data is generated using an insecure method.

  Writes and testing copying
Writing to the disk is possible. If you do this the plugin will check that what you are writing exactly matches what would be read at the same offset (if not, it returns EIO error). You can use this to test copying programs by making the source and destination NBD URIs be the same:

 nbdkit random size=100M --run 'nbdcopy "$uri" "$uri"'

"qemu-img convert" could be used in place of nbdcopy. See also nbdkit-checkwrite-filter(1).

PARAMETERS

fast=true
    Instead of generating completely random data, a single sector of random data is generated when the plugin starts up, which is duplicated across the disk with variations.

[size=]SIZE
    Specify the virtual size of the disk image.

    This parameter is required.

    "size=" prefix may be omitted in most cases. See "Magic parameters" in nbdkit(1).

seed=SEED
    Specify the random seed to get repeatable data over multiple runs.

    If not specified then a random seed is chosen.

FILES

$plugindir/nbdkit-random-plugin.so
    The plugin.

    Use "nbdkit --dump-config" to find the location of $plugindir.

VERSION
"nbdkit-random-plugin" first appeared in nbdkit 1.4.

SEE ALSO
nbdkit(1), nbdkit-plugin(3), nbdkit-data-plugin(1), nbdkit-full-plugin(1), nbdkit-null-plugin(1), nbdkit-ones-plugin(1), nbdkit-pattern-plugin(1), nbdkit-sparse-random-plugin(1), nbdkit-zero-plugin(1), nbdcopy(1), qemu-img(1).

AUTHORS
Richard W.M. Jones

COPYRIGHT
Copyright Red Hat

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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