jammy (1) nbdkit-stats-filter.1.gz

Provided by: nbdkit_1.24.1-2ubuntu4_amd64 bug

NAME
       nbdkit-stats-filter - display statistics about operations


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


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


EXAMPLE
       In this example we run guestfish(1) over nbdkit to create an ext4 filesystem on a RAM disk, and use the
       stats filter to display the number of read, write and trim operations involved:

        $ nbdkit -U - --filter=stats memory 1G statsfile=/dev/stderr \
                 --run '
              guestfish add-drive "" protocol:nbd server:unix:$unixsocket \
                                     discard:enable format:raw : \
                        run : \
                        mkfs ext4 /dev/sda
        '
        total: 370 ops, 1.282993 s, 1.04 GiB, 827.29 MiB/s
        read: 250 ops, 0.000364 s, 4.76 MiB, 12.78 GiB/s op, 3.71 MiB/s total
        write: 78 ops, 0.175715 s, 32.64 MiB, 185.78 MiB/s op, 25.44 MiB/s total
        trim: 33 ops, 0.000252 s, 1.00 GiB, 3968.25 GiB/s op, 798.13 MiB/s total
        flush: 9 ops, 0.000002 s, 0 bytes, 0 bytes/s op, 0 bytes/s total


PARAMETERS
       statsfile=FILE
           The file where we write the stats.

           This parameter is required.

       statsappend=true
           If set then we append to the file instead of replacing it.


FILES
       $filterdir/nbdkit-stats-filter.so
           The filter.

           Use "nbdkit --dump-config" to find the location of $filterdir.


VERSION
       "nbdkit-stats-filter" first appeared in nbdkit 1.14.


SEE ALSO
       nbdkit(1), nbdkit-filter(3), nbdkit-log-filter(1).


AUTHORS
       Richard W.M. Jones


       Copyright (C) 2019 Red Hat Inc.


LICENSE
       Redistribution and use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list of conditions and
           the following disclaimer.

       •   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
           the following disclaimer in the documentation and/or other materials provided with the distribution.

       •   Neither the name of Red Hat nor the names of its contributors may be used to endorse or promote
           products derived from this software without specific prior written permission.

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