Re: Does \"32.1% non-contigunous\" mean severely fragmented?

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To: Tetsuo Handa <penguin-kernel@...>
Cc: <linux-fsdevel@...>
Date: Friday, October 19, 2007 - 2:52 pm

On Fri, Oct 19, 2007 at 10:49:03AM +0900, Tetsuo Handa wrote:


Not necessarily; it just means that 32% of your files have at least
one discontinuity.  Given the ext3 layout, by definition every 128
megs there will be a discontinuity because of the metadata at the
beginning of every single block group.  You have a small number of
files on your system (349) occupying an average of 348 megabytes.  So
it's not at all surprising that the contiguous percentage is 32%.

The recent Flex BG feature that was recently pulled into 2.6.23-git14
for ext4 is desgined to avoid this issue, but a seek every 128 megs is
for most workloads not a big deal and will hopefully not cause you any
problems.

							- Ted
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Messages in current thread:
Re: Does \"32.1% non-contigunous\" mean severely fragmented?, Theodore Tso, (Fri Oct 19, 2:52 pm)
Re: Does "32.1% non-contiguous" mean severely fragmented?, Tetsuo Handa, (Fri Oct 19, 11:39 pm)