From owner-freebsd-questions Thu May 24 18:51:43 2001 Delivered-To: freebsd-questions@freebsd.org Received: from clmboh1-smtp3.columbus.rr.com (clmboh1-smtp3.columbus.rr.com [65.24.0.112]) by hub.freebsd.org (Postfix) with ESMTP id 90B9A37B422 for ; Thu, 24 May 2001 18:51:39 -0700 (PDT) (envelope-from wmoran@iowna.com) Received: from iowna.com (dhcp065-024-023-038.columbus.rr.com [65.24.23.38]) by clmboh1-smtp3.columbus.rr.com (8.11.2/8.11.2) with ESMTP id f4P1mOk01259; Thu, 24 May 2001 21:48:25 -0400 (EDT) Message-ID: <3B0DBA59.14E1D208@iowna.com> Date: Thu, 24 May 2001 21:50:17 -0400 From: Bill Moran X-Mailer: Mozilla 4.76 [en] (X11; U; FreeBSD 4.3-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: Jonathan Chen Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Remount Filesystems References: <20010525094056.B37339@itouchnz.itouch> <3B0D8A80.596CC3B7@iowna.com> <20010525103021.B40969@itouchnz.itouch> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Jonathan Chen wrote: > > On Thu, May 24, 2001 at 06:26:09PM -0400, Bill Moran wrote: > > [...] > > I don't understand why you'd bother with softupdates on / anyway? Just > > from my perspective, I try to keep the / fs as reliable as possible and, > > although softupdates is very reliable, it does have a slightly higher > > incidence of crash corruption than standard sync. > > Really? My understanding of softupdates was that it keeps that metadata > in a more stable state, and thus makes your filesystem *less* prone to > fsck problems. > > Otherwise, why would anyone want to enable softupdates on a production > system? No, softupdates is a compromise between the speed of async and the reliability of sync. Unfortunately I'm not terribly familiar with the technical details, but in order of reliability it's sync->softupdates->async while speed is async->softupdates->sync. Keep in mind that all are reliable under normal conditions, it's only abnormal conditions (like power failure) that cause problems. /usr/src/contrib/sys/softupdates/README may have more details for you, but I accidentally blew away my source tree the other day, so I'm not 100% sure what's in that file, and I can't remember exactly where I learned this from initially, or I'd point you there. -Bill To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message