Am Montag, 1. Oktober 2012 schrieb Matt Hayward:
> Hello,
Hi Matt,
> I frequently want to perform a set amount (e.g. 1 GB) of random I/O
> over very large files or devices (e.g. 1 TB).
>
> I have noticed that when using the "size" argument to control the
> amount of I/O, it also has the side effect of constraining the I/O to
> the first "size" bytes of the file.
>
> Is there a way to tell FIO to perform X bytes of random I/O on a
> file of size Y and have the random I/O distributed throughout the
> extent of Y where Y > X?
How about
offset=int
Offset in the file to start I/O. Data before the offset will
not be touched.
offset_increment=int
If this is provided, then the real offset becomes the offset
+ offset_increment * thread_number, where the thread number
is a counter that starts at 0 and is incremented for each
job. This option is useful if there are several jobs which
are intended to operate on a file in parallel in disjoint
segments, with even spacing between the starting points.
Thanks,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7
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