diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2015-07-13 13:13:17 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2016-06-08 10:21:09 +0200 |
| commit | 83de9be0dc59439ec6f97f58c8e9015b4fdc3010 (patch) | |
| tree | cbc458a208601fe3113bc8313f992204ddb03da0 /qemu-img.texi | |
| parent | d3199a31c7bc72f6bcecbb3ebcc16940a1721e10 (diff) | |
qemu-img bench: Implement -S (step size)
With this new option, qemu-img bench can be told to advance the current
offset after each request by a different value than the buffer size.
This is useful for controlling the conditions for cluster allocation in
image formats (e.g. qcow2 cluster allocation with COW in front of the
request, or COW areas that aren't overwritten immediately).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qemu-img.texi')
| -rw-r--r-- | qemu-img.texi | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/qemu-img.texi b/qemu-img.texi index 9bffad226b..ccc0b519ba 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -131,14 +131,16 @@ Skip the creation of the target volume Command description: @table @option -@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [-n] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-t @var{cache}] [-w] @var{filename} +@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [-n] [-o @var{offset}] [--pattern=@var{pattern}] [-q] [-s @var{buffer_size}] [-S @var{step_size}] [-t @var{cache}] [-w] @var{filename} Run a simple sequential I/O benchmark on the specified image. If @code{-w} is specified, a write test is performed, otherwise a read test is performed. A total number of @var{count} I/O requests is performed, each @var{buffer_size} bytes in size, and with @var{depth} requests in parallel. The first request -starts at the position given by @var{offset}. +starts at the position given by @var{offset}, each following request increases +the current position by @var{step_size}. If @var{step_size} is not given, +@var{buffer_size} is used for its value. If @code{-n} is specified, the native AIO backend is used if possible. On Linux, this option only works if @code{-t none} or @code{-t directsync} is |