1nbdkit-stats-filter(1) NBDKIT nbdkit-stats-filter(1)
2
6 nbdkit-stats-filter - display statistics about operations
7
9 nbdkit --filter=stats PLUGIN statsfile=FILE
10 [statsappend=true] [statsthreshold=PERCENTILE]
11
13 "nbdkit-stats-filter" is a filter that displays statistics about NBD
14 operations, such as the number of bytes read and written. Statistics
15 are written to a file once when nbdkit exits.
16
18 # nbdkit --filter=exitlast --filter=stats memory 25G statsfile=example.txt
19 # nbd-client localhost /dev/nbd1 && mkfs.ext4 /dev/nbd1 && sync &&
20 nbd-client -d /dev/nbd1
21 [....]
22 # cat example.txt
23 total: 191 ops, 21.917545 s, 25.13 GiB, 1.15 GiB/s
24 read: 136 ops, 0.000230 s, 3.16 MiB, 13.43 GiB/s op, 147.83 KiB/s total
25 Request size and alignment breakdown:
26 12 bits: 68.4% (93 reqs, 372.00 KiB total)
27 12 bit aligned: 100.0% (93)
28 13 bit aligned: 72.0% (67)
29 14 bit aligned: 55.9% (52)
30 15 bit aligned: 48.4% (45)
31 16 bit aligned: 43.0% (40)
32 14 bits: 10.3% (14 reqs, 296.00 KiB total)
33 12 bit aligned: 100.0% (14)
34 13 bit aligned: 35.7% (5)
35 19 bit aligned: 21.4% (3)
36 [....]
37 other sizes: 3.7% (5 reqs, 3.16 MiB total)
38 write: 36 ops, 0.125460 s, 132.38 MiB, 1.03 GiB/s op, 6.04 MiB/s total
40 Request size and alignment breakdown:
41 12 bits: 50.0% (18 reqs, 72.00 KiB total)
42 12 bit aligned: 100.0% (18)
43 13 bit aligned: 77.8% (14)
44 27 bit aligned: 72.2% (13)
45 31 bit aligned: 66.7% (12)
46 32 bit aligned: 33.3% (6)
47 33 bit aligned: 22.2% (4)
48 34 bit aligned: 11.1% (2)
49 14 bits: 30.6% (11 reqs, 224.00 KiB total)
50 12 bit aligned: 100.0% (11)
51 27 bit aligned: 90.9% (10)
52 25 bits: 11.1% (4 reqs, 128.00 MiB total)
53 25 bit aligned: 100.0% (4)
54 26 bit aligned: 50.0% (2)
55 27 bit aligned: 25.0% (1)
56 16 bits: 2.8% (1 reqs, 64.00 KiB total)
57 16 bit aligned: 100.0% (1)
58 trim: 14 ops, 0.002687 s, 25.00 GiB, 9304.06 GiB/s op, 1.14 GiB/s total
60 Request size and alignment breakdown:
61 31 bits: 85.7% (12 reqs, 24.00 GiB total)
62 24 bit aligned: 100.0% (12)
63 24 bits: 7.1% (1 reqs, 16.00 MiB total)
64 flush: 5 ops, 0.000002 s, 0 bytes, 0 bytes/s op, 0 bytes/s total
66
68 statsfile=FILE
69 The file where we write the stats.
70 This parameter is required.
72 statsappend=true
74 If set then we append to the file instead of replacing it.
75 statsthreshold=PERCENTILE
77 If non-zero, track request size and alignment distribution and
78 print histogram.
79 Requests are grouped by the number of bits that are needed to
81 represent the request size (e.g. a request of size 3892 needs will
82 be grouped with all requests of size 2^11=2048 to 2^12-1=4095), and
83 the number of trailing zero bits in the offset.
84 Histogram output is truncated to PERCENTILE of requests. Default:
86 95.
87
89 $filterdir/nbdkit-stats-filter.so
90 The filter.
91 Use "nbdkit --dump-config" to find the location of $filterdir.
93
95 "nbdkit-stats-filter" first appeared in nbdkit 1.14.
96
98 nbdkit(1), nbdkit-filter(3), nbdkit-log-filter(1).
99
101 Richard W.M. Jones
102 Nikolaus Rath
104
106 Copyright (C) 2019-2022 Red Hat Inc.
107
109 Redistribution and use in source and binary forms, with or without
110 modification, are permitted provided that the following conditions are
111 met:
112 • Redistributions of source code must retain the above copyright
114 notice, this list of conditions and the following disclaimer.
115 • Redistributions in binary form must reproduce the above copyright
117 notice, this list of conditions and the following disclaimer in the
118 documentation and/or other materials provided with the
119 distribution.
120 • Neither the name of Red Hat nor the names of its contributors may
122 be used to endorse or promote products derived from this software
123 without specific prior written permission.
124 THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY
126 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
127 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
128 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE
129 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
130 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
131 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
132 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
133 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
134 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
135 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
136nbdkit-1.32.5 2023-01-03 nbdkit-stats-filter(1)