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From: Richard Ems <richard.ems@cape-horn-eng.com>
To: Dave Chinner <david@fromorbit.com>
Cc: xfs@oss.sgi.com
Subject: Re: cannot defrag volume, fragmentation factor 21.73%
Date: Fri, 22 Oct 2010 12:12:27 +0200	[thread overview]
Message-ID: <4CC1638B.4070807@cape-horn-eng.com> (raw)
In-Reply-To: <20101018231009.GL29677@dastard>

On 10/19/2010 01:10 AM, Dave Chinner wrote:
> Understand your numbers. What frag reports is how many extents there
> are vs a perfect layout. It does not tell you how badly fragmented
> your filesystem is. Extent-based filesystems can have
> "fragmentation" like you see reported above, but not suffer at all
> because the extents are large enough not to affect IO throughput.

Hi Dave,

I think I almost got that now.
But, at which numbers should I look at before starting a defrag then?

Up to now, I ran always "echo frag | xfs_db -r /dev/..." to get a 
"number" that could tell me if starting a xfs_fsr was necessary.

At which other numbers should I look at to see if running a xfs_fsr 
defrag is necessary or not?

Many thanks,
Richard


-- 
Richard Ems       mail: Richard.Ems@Cape-Horn-Eng.com

Cape Horn Engineering S.L.
C/ Dr. J.J. Dómine 1, 5º piso
46011 Valencia
Tel : +34 96 3242923 / Fax 924
http://www.cape-horn-eng.com

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  parent reply	other threads:[~2010-10-22 10:11 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-18 12:09 cannot defrag volume, fragmentation factor 21.73% Richard Ems
2010-10-18 12:39 ` Michael Monnerie
2010-10-18 13:46   ` Richard Ems
2010-10-18 17:58     ` Michael Monnerie
2010-10-18 20:16 ` Stan Hoeppner
2010-10-18 23:10 ` Dave Chinner
2010-10-19  9:37   ` Richard Ems
2010-10-22 10:12   ` Richard Ems [this message]
2010-10-22 21:02     ` Michael Monnerie

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