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.

AUTHORS

Richard W.M. Jones

COPYRIGHT

LICENSE

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