From: Jens Axboe <jens.axboe@oracle.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: fio@vger.kernel.org
Subject: Re: Writing to /dev/null with fio
Date: Tue, 2 Feb 2010 08:41:35 +0100 [thread overview]
Message-ID: <20100202074135.GX13771@kernel.dk> (raw)
In-Reply-To: <e2e108261002012338j62fd1983x7f4a0122d3fd97a4@mail.gmail.com>
On Tue, Feb 02 2010, Bart Van Assche wrote:
> Hello Jens,
>
> I noticed that writing with fio to /dev/null takes much more time (220
> times more for the test below) than with dd. Did I specify the correct
> arguments to fio ? If so, is this known behavior of fio ?
>
> $ dd if=/dev/zero of=/dev/null bs=1M count=1024
> 1024+0 records in
> 1024+0 records out
> 1073741824 bytes (1.1 GB) copied, 0.121485 s, 8.8 GB/s
>
> $ fio --bs=1M --size=1G --buffered=1 --rw=write --verify=0
> --name=dev-null /dev/null
You are writing to a file named dev-null and /dev/null is being ignored
as an argument. You want a --filename=/dev/null at the end instead.
--
Jens Axboe
next prev parent reply other threads:[~2010-02-02 7:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-02 7:38 Writing to /dev/null with fio Bart Van Assche
2010-02-02 7:41 ` Jens Axboe [this message]
2010-02-02 8:01 ` Bart Van Assche
2010-02-02 8:19 ` Jens Axboe
2010-02-02 8:24 ` Bart Van Assche
2010-02-02 8:31 ` Jens Axboe
2010-02-02 8:53 ` Jens Axboe
2010-02-02 9:06 ` Bart Van Assche
2010-02-02 9:08 ` Jens Axboe
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