From owner-freebsd-stable  Tue May  8  1:38: 3 2001
Delivered-To: freebsd-stable@freebsd.org
Received: from subnet.sub.net (subnet.sub.net [212.227.14.21])
	by hub.freebsd.org (Postfix) with ESMTP id ABBF137B422
	for <stable@freebsd.org>; Tue,  8 May 2001 01:38:00 -0700 (PDT)
	(envelope-from wolfgang@lyxys.ka.sub.org)
Received: from lyxys.ka.sub.org (uucp@localhost)
	by subnet.sub.net (8.8.8/8.8.8/1.2subnet-linux) with bsmtp id KAA22868;
	Tue, 8 May 2001 10:37:57 +0200
Received: from localhost (1463 bytes) by lyxys.ka.sub.org
	via sendmail with P:stdio/R:smart_host/T:inet_uusmtp
	(sender: <wolfgang>) (ident <wolfgang> using unix)
	id <m14x2xf-003pRhC@lyxys.ka.sub.org>
	for <stable@freebsd.org>; Tue, 8 May 2001 10:35:15 +0200 (CEST)
	(Smail-3.2.0.111 2000-Feb-17 #1 built 2000-Aug-23)
Message-Id: <m14x2xf-003pRhC@lyxys.ka.sub.org>
From: wolfgang@lyxys.ka.sub.org (Wolfgang Zenker)
Subject: Re: What's the conclusion? (was soft update should be default)
In-Reply-To: <20010508010236.30ada34b.tadayuki@mediaone.net> "from Tadayuki OKADA
 at May 8, 2001 01:02:36 am"
To: Tadayuki OKADA <tadayuki@mediaone.net>
Date: Tue, 8 May 2001 10:35:14 +0200 (CEST)
Cc: stable@freebsd.org
X-Mailer: ELM [version 2.4ME+ PL88 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
Sender: owner-freebsd-stable@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

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).
> If this is the only problem, I think softupdates should be the default.
> Because:
> 'write caching' is not the default. Anyone who wants it can disable softupdates.
> Besides it seems 'write caching' is not recommended for the usual usage.

> If you have other resons not to do so, could you please explain it?

softupdates has a problem if you replace lots of files on small filesystems.
If you delete a file on a file system with soft updates enabled, the free
space is committed back to the file system only some time later. Now if
you run a installworld with default slice sizes you could run into problems
cause the replaced files still take up room on your disk for some time while
you need the space for your new files.

Wolfgang

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message