From owner-freebsd-hackers Sun Oct 5 21:31:50 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id VAA01977 for hackers-outgoing; Sun, 5 Oct 1997 21:31:50 -0700 (PDT) (envelope-from owner-freebsd-hackers) Received: from usr09.primenet.com (tlambert@usr09.primenet.com [206.165.6.209]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id VAA01968; Sun, 5 Oct 1997 21:31:43 -0700 (PDT) (envelope-from tlambert@usr09.primenet.com) Received: (from tlambert@localhost) by usr09.primenet.com (8.8.5/8.8.5) id VAA20970; Sun, 5 Oct 1997 21:31:42 -0700 (MST) From: Terry Lambert Message-Id: <199710060431.VAA20970@usr09.primenet.com> Subject: Re: mount async and possible loss of F/S To: ahd@FreeBSD.ORG (Drew Derbyshire) Date: Mon, 6 Oct 1997 04:31:42 +0000 (GMT) Cc: hackers@hub.freebsd.org In-Reply-To: <199710060106.SAA21602@hub.freebsd.org> from "Drew Derbyshire" at Oct 5, 97 06:06:16 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > The mount command cheerfully states that the async option is not to be used > unless you are prepared to recreate the file system. Ummm, exactly > what is left so hanging in the wind that you lose the file system rather > than just the recent updates? The fsck utility can recover exactly one state transition. Any more, and it will return the FS to a "known good state" -- but will it be the "known good state" the FS was supposed to have been in? The naser is that if there were 10 transations outstanding, there is only one known good state. That means a 1 in 2^10 or 1 in 1024 chance of getting the "right" "known good state". Pretty bad odds... but feel free to gamble; the freedom to gamble is an evolutionary pressure which promotes the ability to do simple math in the losers. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.