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From: Troels Arvin <troels@arvin.dk>
To: fio@vger.kernel.org
Subject: Does fio write only 0x00s?
Date: Mon, 15 Mar 2010 21:50:26 +0100	[thread overview]
Message-ID: <4B9E9D92.80701@arvin.dk> (raw)

Hello,

I'm benchmarking a new FC-attached storage system which we are bringing 
into production, in order to see if it yields acceptable performance - 
and to have a baseline for potential performance trouble in the future.

One of the tools I'm using is fio, which is certainly great. Especially 
the fact that it includes data regarding latencies, and that it makes it 
easy to have a mix of reads and writes.

Now, compared to an another FC-attached storage system, and compared to 
a local RAID10, the new system yields fio numbers which are extremely 
much better.
This made me have a quick and superficial look into the files which fio 
works with. I seems that the files contain only 0-bytes.

Does fio only write bytes with a single value?
If so: I would be afraid that some kind of 
compression/de-duplication/thin provisioning feature in the storage 
system invalidates the fio results I'm seeing. Is this a valid fear?

-- 
Regards,
Troels Arvin <troels@arvin.dk>
http://troels.arvin.dk/

             reply	other threads:[~2010-03-15 20:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-15 20:50 Troels Arvin [this message]
2010-03-15 21:22 ` Does fio write only 0x00s? Jens Axboe
2010-03-15 23:19   ` Troels Arvin
2010-03-16  8:05     ` Jens Axboe
2010-03-16 11:27       ` Troels Arvin

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