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From: Eric Sandeen <sandeen@sandeen.net>
To: Gim Leong Chin <chingimleong@yahoo.com.sg>
Cc: xfs@oss.sgi.com
Subject: Re: allocsize mount option
Date: Thu, 14 Jan 2010 11:42:11 -0600	[thread overview]
Message-ID: <4B4F5773.8050409@sandeen.net> (raw)
In-Reply-To: <264613.60659.qm@web76207.mail.sg1.yahoo.com>

Gim Leong Chin wrote:
> Hi Dave,
> 
> 
>> fragmented, it just means that that there are 19% more fragments 
>> than the ideal. In 4TB of data with 1GB sized files, that would
>> mean there are 4800 extents (average length ~800MB, which is 
>> excellent) instead of the perfect 4000 extents (@1GB each). Hence
>> you can see how misleading this "19% fragmentation" number can be
>> on an extent based filesystem...
> 
> There are many files that are 128 GB.
> 
> When I did the tests with dd on this computer, the 20 GB files had up
> to > 50 extents.

which is at least 400mb per extent, which is really not so bad.

-Eric

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  reply	other threads:[~2010-01-14 17:41 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-14 17:25 allocsize mount option Gim Leong Chin
2010-01-14 17:42 ` Eric Sandeen [this message]
2010-01-14 23:28 ` Dave Chinner
  -- strict thread matches above, loose matches on Subject: below --
2011-01-20 20:41 Peter Vajgel
2011-01-21  0:48 ` Dave Chinner
2010-09-28 18:53 Ivan.Novick
2010-09-29  0:31 ` Dave Chinner
2010-01-24  6:44 Gim Leong Chin
2010-01-15  3:08 Gim Leong Chin
2010-01-13  9:42 Gim Leong Chin
2010-01-13 10:50 ` Dave Chinner
2010-01-11 17:25 Gim Leong Chin
2010-01-11 18:16 ` Eric Sandeen

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