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.
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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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SEE ALSO

71       nbdkit(1), nbdkit-plugin(3), nbdkit-split-plugin(1),
72       nbdkit-partitioning-plugin(1), nbdkit-noextents-filter(1).
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AUTHORS

75       Eric Blake
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77       Nir Soffer
78
79       Richard W.M. Jones
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82       Copyright (C) 2013-2018 Red Hat Inc.
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LICENSE

85       Redistribution and use in source and binary forms, with or without
86       modification, are permitted provided that the following conditions are
87       met:
88
89       ·   Redistributions of source code must retain the above copyright
90           notice, this list of conditions and the following disclaimer.
91
92       ·   Redistributions in binary form must reproduce the above copyright
93           notice, this list of conditions and the following disclaimer in the
94           documentation and/or other materials provided with the
95           distribution.
96
97       ·   Neither the name of Red Hat nor the names of its contributors may
98           be used to endorse or promote products derived from this software
99           without specific prior written permission.
100
101       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
102       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
103       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
104       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
105       LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
106       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
107       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
108       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
109       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
110       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
111       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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115nbdkit-1.12.3                     2019-05-22             nbdkit-file-plugin(1)
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