Re: Large disk partition over 300GB

Rick Bressler (rick.bressler@boeing.com)
Tue, 13 Jul 1999 18:48:58 -0700 (PDT)


> BUT, when it's a 300 GB partition, does the filesystem really need 5% of
> 300GB?
>
> ie, 300GB*5% = 15GB reserved space.

Well, ideally you want some in each cylinder group. 'Enough' was
originally arrived at as I recall by quantitative testing on much
smaller drives. Might be time for a retest.

The purpose of this addendum is not to address that, but to point out
that there are times when -m0 is quite reasonable. Those times are when
the disk files are created once, and the file allocations don't change.

Oracle data tables are such an example. While the tables themselves
change, the data appears 'static' from a filesystem metadata standpoint
and there is no point is setting -m to anything but 0.

If you have a very dynamic filesystem, particularly one that creates and
deletes many large files, you may find performance much better with -m
set to 10 percent or more!

Speed is always a tradeoff.

-- 
+--------------------------------------------+ Rick Bressler
|Mushrooms and other fungi have several      | 
|important roles in nature.  They help things|
|grow, they are a source of food, they       |
|decompose organic matter and they           | bressler@mushroom.ca.boeing.com
|infect, debilitate and kill organisms.      | 
+--------------------------------------------+ 

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