On 12/15/22 10:56, Shin'ichiro Kawasaki wrote: > The options max_open_zones and job_max_open_zones control the number of > open zones for zonemode=zbd. However, descriptions in HOWTO and man > about these options are not clear enough since it is not well described > what an open zone is. Improve the description by adding explanation of > the open zone state. Also explain the default values for these options. > > Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx> > --- > HOWTO.rst | 27 ++++++++++++++++++++------- > fio.1 | 23 +++++++++++++++++------ > 2 files changed, 37 insertions(+), 13 deletions(-) > > diff --git a/HOWTO.rst b/HOWTO.rst > index 5a5263c3..ad43d162 100644 > --- a/HOWTO.rst > +++ b/HOWTO.rst > @@ -1052,16 +1052,29 @@ Target file/device > > .. option:: max_open_zones=int > > - When running a random write test across an entire drive many more > - zones will be open than in a typical application workload. Hence this > - command line option that allows one to limit the number of open zones. The > - number of open zones is defined as the number of zones to which write > - commands are issued. > + A zone of a zoned block device is in the open state when it is partially > + written (i.e. not all sectors of the zone have been written). Zoned > + block devices may have limitation on the total number of zones that can may have limitation -> may have a limit on (my bad) > + be simultaneously in the open state, that is, the number of zones that > + can be written to simultaneously. The :option:`max_open_zones` parameter > + limits the number of zones to which write commands are issued by all fio > + jobs, that is, limits the number of zones that will be in the open > + state. This parameter is relevant only if the :option:`zonemode` =zbd is > + used. The default value is always equal to maximum number of open zones > + of the target zoned block device and a value higher than this limit > + cannot be specified by users unless the option > + :option:`ignore_zone_limits` is specified. When > + :option:`ignore_zone_limits` is specified or the target device has no > + limit on the number of zones that can be in an open state, > + :option:`max_open_zones` can specify 0 to disable any limit on the > + number of zones that can be simultaneously written to by all jobs. > > .. option:: job_max_open_zones=int > > - Limit on the number of simultaneously opened zones per single > - thread/process. > + In the same manner as :option:`max_open_zones`, limit the number of open > + zones per fio job, that is, the number of zones that a single job can > + simultaneously write to. A value of zero indicates no limit. > + Default: zero. > > .. option:: ignore_zone_limits=bool > > diff --git a/fio.1 b/fio.1 > index a0d765e5..d6ad0e27 100644 > --- a/fio.1 > +++ b/fio.1 > @@ -828,14 +828,25 @@ numbers fio only reads beyond the write pointer if explicitly told to do > so. Default: false. > .TP > .BI max_open_zones \fR=\fPint > -When running a random write test across an entire drive many more zones will be > -open than in a typical application workload. Hence this command line option > -that allows one to limit the number of open zones. The number of open zones is > -defined as the number of zones to which write commands are issued by all > -threads/processes. > +A zone of a zoned block device is in the open state when it is partially written > +(i.e. not all sectors of the zone have been written). Zoned block devices may > +have limitation on the total number of zones that can be simultaneously in the > +open state, that is, the number of zones that can be written to simultaneously. > +The \fBmax_open_zones\fR parameter limits the number of zones to which write > +commands are issued by all fio jobs, that is, limits the number of zones that > +will be in the open state. This parameter is relevant only if the > +\fBzonemode=zbd\fR is used. The default value is always equal to maximum number > +of open zones of the target zoned block device and a value higher than this > +limit cannot be specified by users unless the option \fBignore_zone_limits\fR is > +specified. When \fBignore_zone_limits\fR is specified or the target device has > +no limit on the number of zones that can be in an open state, > +\fBmax_open_zones\fR can specify 0 to disable any limit on the number of zones > +that can be simultaneously written to by all jobs. > .TP > .BI job_max_open_zones \fR=\fPint > -Limit on the number of simultaneously opened zones per single thread/process. > +In the same manner as \fBmax_open_zones\fR, limit the number of open zones per > +fio job, that is, the number of zones that a single job can simultaneously write > +to. A value of zero indicates no limit. Default: zero. > .TP > .BI ignore_zone_limits \fR=\fPbool > If this option is used, fio will ignore the maximum number of open zones limit -- Damien Le Moal Western Digital Research
