From owner-freebsd-questions Sat Aug 26 23:33:40 2000 Delivered-To: freebsd-questions@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 68C7C37B42C for ; Sat, 26 Aug 2000 23:33:32 -0700 (PDT) Received: (from grog@localhost) by wantadilla.lemis.com (8.9.3/8.9.3) id QAA51124; Sun, 27 Aug 2000 16:03:26 +0930 (CST) (envelope-from grog) Date: Sun, 27 Aug 2000 16:03:25 +0930 From: Greg Lehey To: Mike Meyer Cc: questions@freebsd.org Subject: Re: read only / filesystem Message-ID: <20000827160325.D88160@wantadilla.lemis.com> References: <78875170@toto.iv> <14760.37457.359972.176638@guru.mired.org> <20000827135500.A88160@wantadilla.lemis.com> <14760.45477.402050.39137@guru.mired.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.4i In-Reply-To: <14760.45477.402050.39137@guru.mired.org>; from mwm@mired.org on Sun, Aug 27, 2000 at 01:13:57AM -0500 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sunday, 27 August 2000 at 1:13:57 -0500, Mike Meyer wrote: > Greg Lehey writes: >> On Saturday, 26 August 2000 at 23:00:17 -0500, Mike Meyer wrote: >>> Greg Lehey writes: >>>> On Thursday, 24 August 2000 at 23:49:17 -0700, R Joseph Wright wrote: >>>>> Or is it easy enough to simply remount / rw when changes to /etc are >>>>> needed? >>>> You can do this, but you can't go back to an ro mount. >>> Uh - why not? >> It's not reliable. There are some problems with dirty buffers when >> you make the file system read-only again. I forget whether it's data >> corruption or a panic, but the only safe way to do this is to umount >> the file system and remount it r/o, obviously not an option here. > > Sounds like an OS bug. The mount system call should make sure the file > system is in sync before doing the udpate mount. You could, of course, > do the sync's by hand until that happens. Sure, it's a bug. But it's not one that interests many people, so nobody has fixed it. Don't underestimate its complexity. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message