From owner-freebsd-stable  Sat May  5  1: 0:33 2001
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Date: Sat, 5 May 2001 00:58:39 -0700 (PDT)
From: Gordon Tetlow <gordont@bluemtn.net>
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To: Nick Sayer <nsayer@quack.kfu.com>
Cc: Mike Smith <msmith@FreeBSD.ORG>,
	Tadayuki OKADA <tadayuki@mediaone.net>, stable <stable@FreeBSD.ORG>
Subject: Re: soft update should be default
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On Fri, 4 May 2001, Nick Sayer wrote:

> Mike Smith wrote:
>
> >> Hi,
> >>
> >> Why 'soft update' is not default?
> >> It adds performance and stability, doesn't it?
> >
> >
> > It requires disabling of write caching, which typically reduces
> > performance (significantly).
> >
> Why wouldn't a similar requirement (disabling write caching) apply to
> non-softupdates filesystems? The disk doesn't know whether the write is
> synchronous or not, after all.

That's the thing about it. If you have write-caching enabled then all bets
are off in any case (ie, you might as well run in async). In addition,
soft updates does some really smart things even over async.

-gordon


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