Re: no unlink file before write testing

On Mon, 2008-04-14 at 12:37 +0200, Jens Axboe wrote:
> On Mon, Apr 14 2008, Jens Axboe wrote:
> > On Tue, Apr 08 2008, Zhang, Yanmin wrote:
> > > Jens,
> > >
> > > As for write testing, fio chooses to unlink the files before testing.
> > > I run the testing on many big files, so the file preparation spends
> > > lots of time. Is it possible to add a new parameter, such like
> > > nounlinkwrite, to ask fio not to unlink files before testing? Its default
> > > value could be false.
> > >
> > > Current parameter overwrite always recreates the files.
> >
> > How about we just change that instead? If the file exists and is big
> > enough, there's no point in having 'overwrite' recreate the file.
>
> That seems to be how overwrite currently behaves (and, anything else
> would have surprised me).
>
> Can you come up with a concrete example that doesn't behave as expected?
You are right. originally, I was misled by function extend_file. After double-checking
it, I find caller setup_files has a checking before setting flag FIO_FILE_EXTEND.

How about change below statement in HOWTO from:

overwrite=bool If writing to a file, setup the file first and do overwrites.

to:

overwrite=bool If writing to a file and extending the file when setup, overwrites the
whole file.

yanmin
Received on Tue Apr 15 2008 - 04:38:19 CEST