Re: ORION results

From: Jared Still <>
Date: Fri, 29 Jan 2010 10:16:57 -0800
Message-ID: <>

On Fri, Jan 29, 2010 at 8:10 AM, D'Hooge Freek <>wrote:

> I think block devices are buffered, so you would need to use raw devices
> (or open de block devices with the O_DIRECT flag).

... or use a benchmark that will obliterate the cache and let you see with real IO of the storage.

I did that once a few years ago and graphed it - it was quite interesting to see IO's come down
and disk utilization go up and meet at a point predicted by reading the spec sheet of the drives.

Unfortunately I seem to have lost that file with the graph in it.

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist Oracle Blog: Home Page:

Received on Fri Jan 29 2010 - 12:16:57 CST

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