From owner-freebsd-current Fri Dec 6 11:30:11 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5845F37B401 for ; Fri, 6 Dec 2002 11:30:10 -0800 (PST) Received: from InterJet.dellroad.org (adsl-63-194-81-26.dsl.snfc21.pacbell.net [63.194.81.26]) by mx1.FreeBSD.org (Postfix) with ESMTP id 71C7043EB2 for ; Fri, 6 Dec 2002 11:30:09 -0800 (PST) (envelope-from archie@dellroad.org) Received: from arch20m.dellroad.org (arch20m.dellroad.org [10.1.1.20]) by InterJet.dellroad.org (8.9.1a/8.9.1) with ESMTP id LAA98854; Fri, 6 Dec 2002 11:29:26 -0800 (PST) Received: from arch20m.dellroad.org (localhost [127.0.0.1]) by arch20m.dellroad.org (8.12.6/8.12.6) with ESMTP id gB6JSqFF065390; Fri, 6 Dec 2002 11:28:52 -0800 (PST) (envelope-from archie@arch20m.dellroad.org) Received: (from archie@localhost) by arch20m.dellroad.org (8.12.6/8.12.6/Submit) id gB6JSqn0065389; Fri, 6 Dec 2002 11:28:52 -0800 (PST) From: Archie Cobbs Message-Id: <200212061928.gB6JSqn0065389@arch20m.dellroad.org> Subject: Re: backgroud fsck is still locking up system (fwd) In-Reply-To: <20021206191024.GA1646@dan.emsphone.com> To: Dan Nelson Date: Fri, 6 Dec 2002 11:28:52 -0800 (PST) Cc: mckusick@beastie.mckusick.com, freebsd-current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL99b (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Dan Nelson wrote: > > Why does softupdates not get enabled on / , by default on the > > install? > > Softupdates updates on-disk structures in the background, and > background fsck cannot relink unreferenced files into lost+found, so > you run the risk of losing both the original and backup copies of > important files in case of a sudden reboot. Imagine you edited > /etc/rc.conf, saved it, and 5 seconds later the system panic'ed. > Because the default metadata flush time is 28 seconds, there's a pretty > good chance that neither the new file or the original is in /etc after > a reboot. I got bit by this three times before I learned my lesson. I I don't understand this.. presumably vi updates the file contents by opening and writing into the file; why would this cause the file's directory entry to disappear? On the other hand, if you do "mv rc.conf.new rc.conf" then you are supposedly guaranteed that the file exists in some form; see rename(2). In any case, you seem to be implying that with respect to modifying files just before a system crash: (a) Softupdates is more 'dangerous' than non-softupdates (b) Background fsck is more 'dangerous' than normal fsck Is this really true? I thought if anything the reverse of (a) would be true. -Archie __________________________________________________________________________ Archie Cobbs * Packet Design * http://www.packetdesign.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message