1nbdkit-pattern-plugin(1) NBDKIT nbdkit-pattern-plugin(1)
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6 nbdkit-pattern-plugin - plugin to serve a fixed pattern of data for
7 testing
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10 nbdkit pattern [size=]SIZE
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13 "nbdkit-pattern-plugin" is a plugin for nbdkit(1) which serves a fixed
14 pattern of data, read only. This is used for testing nbdkit filters
15 and NBD clients. To create test disks filled with other repeated
16 patterns use nbdkit-data-plugin(1) instead.
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18 The fixed pattern is the offset, as a 64 bit big endian integer, every
19 8 bytes. In hexadecimal this looks like:
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21 offset data
22 0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 08
23 0010: 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00 18
24 0020: 00 00 00 00 00 00 00 20 00 00 00 00 00 00 00 28
25 ↗ └──────────┬──────────┘
26 byte at offset 0x28 │
27 │
28 64 bit big endian int
29 encoding offset 0x28
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31 The size of the virtual disk must be specified using the "size"
32 parameter. If the size is not a multiple of 8 then the last 8 byte
33 offset in the pattern is truncated.
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35 Largest possible size
36 nbdkit itself limits plugins to 2⁶³-1 bytes
37 (decimal: 9223372036854775807, hexadecimal: 0x7fff_ffff_ffff_ffff).
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39 To test if NBD clients are free of bugs (not to mention nbdkit itself)
40 you can use:
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42 nbdkit pattern 9223372036854775807
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44 Note this is too large for qemu to open.
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46 Little endian pattern
47 To get a little endian pattern instead of big endian apply
48 nbdkit-swab-filter(1) on top of this plugin:
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50 nbdkit pattern 1G --filter=swab swab-bits=64
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53 [size=]SIZE
54 Specify the virtual size of the disk image.
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56 This parameter is required.
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58 "size=" is a magic config key and may be omitted in most cases.
59 See "Magic parameters" in nbdkit(1).
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62 $plugindir/nbdkit-pattern-plugin.so
63 The plugin.
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65 Use "nbdkit --dump-config" to find the location of $plugindir.
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68 "nbdkit-pattern-plugin" first appeared in nbdkit 1.6.
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71 nbdkit(1), nbdkit-plugin(3), nbdkit-data-plugin(1),
72 nbdkit-full-plugin(1), nbdkit-null-plugin(1), nbdkit-offset-filter(1),
73 nbdkit-random-plugin(1), nbdkit-sparse-random-plugin(1),
74 nbdkit-swab-filter(1), nbdkit-zero-plugin(1).
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77 Richard W.M. Jones
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80 Copyright (C) 2018 Red Hat Inc.
81
83 Redistribution and use in source and binary forms, with or without
84 modification, are permitted provided that the following conditions are
85 met:
86
87 • Redistributions of source code must retain the above copyright
88 notice, this list of conditions and the following disclaimer.
89
90 • Redistributions in binary form must reproduce the above copyright
91 notice, this list of conditions and the following disclaimer in the
92 documentation and/or other materials provided with the
93 distribution.
94
95 • Neither the name of Red Hat nor the names of its contributors may
96 be used to endorse or promote products derived from this software
97 without specific prior written permission.
98
99 THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
100 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
101 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
102 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
103 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
104 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
105 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
106 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
107 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
108 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
109 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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113nbdkit-1.28.2 2021-11-09 nbdkit-pattern-plugin(1)