Provided by: nbdkit_1.36.3-1ubuntu10_amd64 
NAME
nbdkit-pattern-plugin - plugin to serve a fixed pattern of data for testing
SYNOPSIS
nbdkit pattern [size=]SIZE
DESCRIPTION
"nbdkit-pattern-plugin" is a plugin for nbdkit(1) which serves a fixed pattern of data, read only. This
is used for testing nbdkit filters and NBD clients. To create test disks filled with other repeated
patterns use nbdkit-data-plugin(1) or nbdkit-ones-plugin(1) instead.
The fixed pattern is the offset, as a 64 bit big endian integer, every 8 bytes. In hexadecimal this
looks like:
offset data
0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 08
0010: 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00 18
0020: 00 00 00 00 00 00 00 20 00 00 00 00 00 00 00 28
↗ └──────────┬──────────┘
byte at offset 0x28 │
│
64 bit big endian int
encoding offset 0x28
The size of the virtual disk must be specified using the "size" parameter. If the size is not a multiple
of 8 then the last 8 byte offset in the pattern is truncated.
Largest possible size
nbdkit itself limits plugins to 2⁶³-1 bytes (decimal: 9223372036854775807,
hexadecimal: 0x7fff_ffff_ffff_ffff).
To test if NBD clients are free of bugs (not to mention nbdkit itself) you can use:
nbdkit pattern 9223372036854775807
Note this is too large for qemu to open.
Little endian pattern
To get a little endian pattern instead of big endian apply nbdkit-swab-filter(1) on top of this plugin:
nbdkit pattern 1G --filter=swab swab-bits=64
PARAMETERS
[size=]SIZE
Specify the virtual size of the disk image.
This parameter is required.
"size=" is a magic config key and may be omitted in most cases. See "Magic parameters" in nbdkit(1).
FILES
$plugindir/nbdkit-pattern-plugin.so
The plugin.
Use "nbdkit --dump-config" to find the location of $plugindir.
VERSION
"nbdkit-pattern-plugin" first appeared in nbdkit 1.6.
SEE ALSO
nbdkit(1), nbdkit-plugin(3), nbdkit-data-plugin(1), nbdkit-full-plugin(1), nbdkit-null-plugin(1),
nbdkit-ones-plugin(1), nbdkit-offset-filter(1), nbdkit-random-plugin(1), nbdkit-sparse-random-plugin(1),
nbdkit-swab-filter(1), nbdkit-zero-plugin(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.
THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
nbdkit-1.36.3 2024-03-31 nbdkit-pattern-plugin(1)