1nbdkit-stats-filter(1)              NBDKIT              nbdkit-stats-filter(1)
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NAME

6       nbdkit-stats-filter - display statistics about operations
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SYNOPSIS

9        nbdkit --filter=stats PLUGIN statsfile=FILE [statsappend=true]
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DESCRIPTION

12       "nbdkit-stats-filter" is a filter that displays statistics about NBD
13       operations, such as the number of bytes read and written.  Statistics
14       are written to a file once when nbdkit exits.
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EXAMPLE

17       In this example we run guestfish(1) over nbdkit to create an ext4
18       filesystem on a RAM disk, and use the stats filter to display the
19       number of read, write and trim operations involved:
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21        $ nbdkit -U - --filter=stats memory 1G statsfile=/dev/stderr \
22                 --run '
23              guestfish add-drive "" protocol:nbd server:unix:$unixsocket \
24                                     discard:enable format:raw : \
25                        run : \
26                        mkfs ext4 /dev/sda
27        '
28        total: 370 ops, 1.282993 s, 1.04 GiB, 827.29 MiB/s
29        read: 250 ops, 0.000364 s, 4.76 MiB, 12.78 GiB/s op, 3.71 MiB/s total
30        write: 78 ops, 0.175715 s, 32.64 MiB, 185.78 MiB/s op, 25.44 MiB/s total
31        trim: 33 ops, 0.000252 s, 1.00 GiB, 3968.25 GiB/s op, 798.13 MiB/s total
32        flush: 9 ops, 0.000002 s, 0 bytes, 0 bytes/s op, 0 bytes/s total
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PARAMETERS

35       statsfile=FILE
36           The file where we write the stats.
37
38           This parameter is required.
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40       statsappend=true
41           If set then we append to the file instead of replacing it.
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FILES

44       $filterdir/nbdkit-stats-filter.so
45           The filter.
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47           Use "nbdkit --dump-config" to find the location of $filterdir.
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VERSION

50       "nbdkit-stats-filter" first appeared in nbdkit 1.14.
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SEE ALSO

53       nbdkit(1), nbdkit-filter(3), nbdkit-log-filter(1).
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AUTHORS

56       Richard W.M. Jones
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59       Copyright (C) 2019 Red Hat Inc.
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LICENSE

62       Redistribution and use in source and binary forms, with or without
63       modification, are permitted provided that the following conditions are
64       met:
65
66       ·   Redistributions of source code must retain the above copyright
67           notice, this list of conditions and the following disclaimer.
68
69       ·   Redistributions in binary form must reproduce the above copyright
70           notice, this list of conditions and the following disclaimer in the
71           documentation and/or other materials provided with the
72           distribution.
73
74       ·   Neither the name of Red Hat nor the names of its contributors may
75           be used to endorse or promote products derived from this software
76           without specific prior written permission.
77
78       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
79       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80       IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
81       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
82       LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
83       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
84       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
85       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
86       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
87       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
88       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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92nbdkit-1.24.2                     2021-03-02            nbdkit-stats-filter(1)
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