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From: Dave Chinner <david@fromorbit.com>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
	Gandalf Corvotempesta <gandalf.corvotempesta@gmail.com>,
	linux-xfs@vger.kernel.org
Subject: Re: agcount for 2TB, 4TB and 8TB drives
Date: Sat, 7 Oct 2017 09:20:31 +1100	[thread overview]
Message-ID: <20171006222031.GU3666@dastard> (raw)
In-Reply-To: <8e6fd742-8767-e786-746d-2b9f2929b98c@sandeen.net>

On Fri, Oct 06, 2017 at 11:18:39AM -0500, Eric Sandeen wrote:
> On 10/6/17 10:38 AM, Darrick J. Wong wrote:
> > On Fri, Oct 06, 2017 at 10:46:20AM +0200, Gandalf Corvotempesta wrote:
> > Semirelated question: for a solid state disk on a machine with high CPU
> > counts do we prefer agcount == cpucount to take advantage of the
> > high(er) iops and lack of seek time to increase parallelism?
> > 
> > (Not that I've studied that in depth.)
> 
> Interesting question.  :)  Maybe harder to answer for SSD black boxes?

Easy: switch to multidisk mode if /sys/block/<dev>/queue/rotational
is zero after doing all the other checks. Then SSDs will get larger
AG counts automatically.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

  reply	other threads:[~2017-10-06 22:20 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-06  8:46 agcount for 2TB, 4TB and 8TB drives Gandalf Corvotempesta
2017-10-06 15:38 ` Darrick J. Wong
2017-10-06 16:18   ` Eric Sandeen
2017-10-06 22:20     ` Dave Chinner [this message]
2017-10-06 22:21       ` Eric Sandeen
2017-10-09  8:05         ` Avi Kivity
2017-10-09 11:23           ` Dave Chinner
2017-10-09 15:46             ` Avi Kivity
2017-10-09 22:03               ` Dave Chinner
2017-10-10  9:07                 ` Avi Kivity
2017-10-10 22:55                   ` Dave Chinner
2017-10-13  8:13                     ` Avi Kivity
2017-10-14 22:42                       ` Dave Chinner
2017-10-15  9:36                         ` Avi Kivity
2017-10-15 22:00                           ` Dave Chinner
2017-10-16 10:00                             ` Avi Kivity
2017-10-16 22:31                               ` Dave Chinner
2017-10-18  7:31                             ` Christoph Hellwig

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