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To: "John S. Dyson" <toor@dyson.iquest.net>
cc: freebsd-current@FreeBSD.ORG, syssgm@dtir.qld.gov.au
Subject: Re: New timeout capability (was Re: cvs commit:....) 
References: <199709230809.DAA06787@dyson.iquest.net>
In-Reply-To: <199709230809.DAA06787@dyson.iquest.net>
    from "John S. Dyson" at "Tue, 23 Sep 1997 03:09:50 -0500"
Date: Tue, 23 Sep 1997 18:18:58 +1000
From: Stephen McKay <syssgm@dtir.qld.gov.au>
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On Tuesday, 23rd September 1997, "John S. Dyson" wrote:

>Stephen McKay said:
>> I've always wanted to know how much it costs to run with 4Kb file system
>> blocks vs 8Kb or now even 16Kb.  Oh, and the real cost of various minfree
>> percentages.  No obligation, of course, but you might be interested too...
>> 
>32K or even 64K should work :-).  With our upcoming dynamic buffer size
>allocation, we could even do 256K? :-).

Gods!  What for?  (Ok, that's just an initial exclamation.)

My curiosity about the 4Kb vs 8Kb derives from the good job the clustering
code does.  If we have good clustering, then why have big block sizes?  They
just move the breakpoints for max file size before indirect blocks are
needed (and similarly the max file size that can have fragments).

Or at least, that's what my simplistic analysis suggests.  Hard numbers
would be much more useful.

Hmm, with 64Kb blocks, we would have 8Kb frags.  Even windoze 95 can do
better than that!

Stephen.