From owner-freebsd-fs Mon Feb 21 17:18:36 2000 Delivered-To: freebsd-fs@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id C2CCB37B53D; Mon, 21 Feb 2000 17:18:33 -0800 (PST) (envelope-from bright@fw.wintelcom.net) Received: (from bright@localhost) by fw.wintelcom.net (8.9.3/8.9.3) id RAA21012; Mon, 21 Feb 2000 17:44:44 -0800 (PST) Date: Mon, 21 Feb 2000 17:44:44 -0800 From: Alfred Perlstein To: Kirk McKusick Cc: fs@freebsd.org, jkh@freebsd.org Subject: Re: changing mount options still can cause damage? Message-ID: <20000221174444.W21720@fw.wintelcom.net> References: <20000220031938.D21720@fw.wintelcom.net> <200002220000.QAA18690@flamingo.McKusick.COM> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <200002220000.QAA18690@flamingo.McKusick.COM>; from mckusick@flamingo.McKusick.COM on Mon, Feb 21, 2000 at 04:00:51PM -0800 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org * Kirk McKusick [000221 16:30] wrote: > Date: Sun, 20 Feb 2000 03:19:38 -0800 > From: Alfred Perlstein > To: fs@freebsd.org > Cc: mckusick@freebsd.org > Subject: changing mount options still can cause damage? > > Is it true that we can still cause major damage to filesystems that > are moved from read-only to read-write or noasync <-> async? > > >From the mount manpage: > > -- > BUGS > It is possible for a corrupted file system to cause a crash. > > Switching a filesystem back and forth between asynchronous and > normal operation or between read/write and read/only access > using ``mount -u'' may gradually bring about severe filesystem > corruption. > -- > > The first bug is understandable, but personally I've never seen the > second happen, is this still a real problem? > > If not I'd like to remove it. > > thanks, > -- > -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] > > Switching between read-only and read-write should never cause filesystem > corruption. Running async can certainly lead to corruption if the > system crashes. There is an indeterminate period of time after the > system has been switched from async to sync before it will be stable > again, but that period will rarely be more than a minute or two. The > act of switching between sync and async should not cause corruption. > It is just the inherent risk of corruption while running async. > > Kirk McKusick Then I vote to remove it, there's no reason we should be slandering ourselves in our own manpages, the async option already describes the dangers pretty clearly. May I axe it? -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message