1nbdkit-file-plugin(1)               NBDKIT               nbdkit-file-plugin(1)
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NAME

6       nbdkit-file-plugin - nbdkit file plugin
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SYNOPSIS

9        nbdkit file [file=]FILENAME
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DESCRIPTION

12       "nbdkit-file-plugin" is a file serving plugin for nbdkit(1).
13
14       It serves the named "FILENAME" over NBD.  Local block devices (eg.
15       /dev/sda) may also be served.
16
17       To concatenate multiple files, use nbdkit-split-plugin(1).
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19       If you want to expose a file that resides on a file system known to
20       have poor lseek(2) performance when searching for holes ("tmpfs" is
21       known to be one such file system), you can use
22       nbdkit-noextents-filter(1) to avoid the penalty of probing for holes.
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PARAMETERS

25       [file=]FILENAME
26           Serve the file named "FILENAME".  A local block device name can
27           also be used here.
28
29           This parameter is required.
30
31           "file=" is a magic config key and may be omitted in most cases.
32           See "Magic parameters" in nbdkit(1).
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34       rdelay
35       wdelay
36           These plugin parameters have been moved to the
37           nbdkit-delay-filter(1) filter.  Modify the command line to add
38           --filter=delay in order to use these parameters.
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DUMP-PLUGIN OUTPUT

41       You can obtain extra information about how the file plugin was compiled
42       by doing:
43
44        nbdkit file --dump-plugin
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46       Some of the fields which may appear are listed below.  Note these are
47       for information only and may be changed or removed at any time in the
48       future.
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50       "file_blksszget=yes"
51       "file_blkzeroout=yes"
52           If both set, the plugin may be able to efficiently zero ranges of
53           block devices, where the driver and block device itself supports
54           this.
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56       "file_falloc_fl_punch_hole=yes"
57           If set, the plugin may be able to punch holes (make sparse) files
58           and block devices.
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60       "file_falloc_fl_zero_range=yes"
61           If set, the plugin may be able to efficiently zero ranges of files
62           and block devices.
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DEBUG FLAG

65       -D file.zero=1
66           This enables very verbose debugging of the NBD zero request.  This
67           can be used to tell if the file plugin is able to zero ranges in
68           the file or block device efficiently or not.
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FILES

71       $plugindir/nbdkit-file-plugin.so
72           The plugin.
73
74           Use "nbdkit --dump-config" to find the location of $plugindir.
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VERSION

77       "nbdkit-file-plugin" first appeared in nbdkit 1.0.
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SEE ALSO

80       nbdkit(1), nbdkit-plugin(3), nbdkit-split-plugin(1),
81       nbdkit-partitioning-plugin(1), nbdkit-noextents-filter(1).
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AUTHORS

84       Eric Blake
85
86       Nir Soffer
87
88       Richard W.M. Jones
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91       Copyright (C) 2013-2018 Red Hat Inc.
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LICENSE

94       Redistribution and use in source and binary forms, with or without
95       modification, are permitted provided that the following conditions are
96       met:
97
98       ·   Redistributions of source code must retain the above copyright
99           notice, this list of conditions and the following disclaimer.
100
101       ·   Redistributions in binary form must reproduce the above copyright
102           notice, this list of conditions and the following disclaimer in the
103           documentation and/or other materials provided with the
104           distribution.
105
106       ·   Neither the name of Red Hat nor the names of its contributors may
107           be used to endorse or promote products derived from this software
108           without specific prior written permission.
109
110       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
111       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
112       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
113       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
114       LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
115       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
116       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
117       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
118       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
119       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
120       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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124nbdkit-1.18.4                     2020-04-16             nbdkit-file-plugin(1)
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