is incremented for each sub-job (i.e. when :option:`numjobs` option is
specified). This option is useful if there are several jobs which are
intended to operate on a file in parallel disjoint segments, with even
- spacing between the starting points.
+ spacing between the starting points. Percentages can be used for this option.
+ If a percentage is given, the generated offset will be aligned to the minimum
+ ``blocksize`` or to the value of ``offset_align`` if provided.
.. option:: number_ios=int