From owner-freebsd-hackers Fri Jan 10 05:32:09 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id FAA11252 for hackers-outgoing; Fri, 10 Jan 1997 05:32:09 -0800 (PST) Received: from terminator.informatik.ba-stuttgart.de (terminator.informatik.ba-stuttgart.de [141.31.1.21]) by freefall.freebsd.org (8.8.4/8.8.4) with ESMTP id FAA11196 for ; Fri, 10 Jan 1997 05:30:20 -0800 (PST) Received: from helbig.informatik.ba-stuttgart.de (helbig.informatik.ba-stuttgart.de [141.31.166.22]) by terminator.informatik.ba-stuttgart.de (8.7.6/8.7.3) with ESMTP id NAA09079; Fri, 10 Jan 1997 13:29:29 +0100 Received: (from wh@localhost) by helbig.informatik.ba-stuttgart.de (8.8.4/8.8.4) id OAA00302; Fri, 10 Jan 1997 14:29:59 +0100 (MET) From: Wolfgang Helbig Message-Id: <199701101329.OAA00302@helbig.informatik.ba-stuttgart.de> Subject: Re: mount -o async on a news servre To: scrappy@hub.org (The Hermit Hacker) Date: Fri, 10 Jan 1997 14:29:58 +0100 (MET) Cc: hackers@freebsd.org In-Reply-To: from The Hermit Hacker at "Jan 10, 97 06:59:08 am" X-Mailer: ELM [version 2.4ME+ PL22 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > Hiya... > > Exactly *how* dangerous is setting a file system to async? I don't know *exactly* but I mount my /usr all the time async. Yesterday I had a system crash, (the system froze during "make world") but it recovered fine. After it I did another "make world" and this was the first one that succeeded. So mounting async does not seem to dangerous. AFAIK the async option turns off writing every directory change to disk immediately. That means directories will be treated like regular files in this respect, i. e. changes will get to disk during the next sync() call or when the corresponding buffer in the buffer cache is needed for another disk i/o. The update(4) process does a sync every 30 min.