From owner-freebsd-hackers Tue Feb 6 10: 8: 3 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from critter.freebsd.dk (flutter.freebsd.dk [212.242.40.147]) by hub.freebsd.org (Postfix) with ESMTP id 054CF37B4EC for ; Tue, 6 Feb 2001 10:07:43 -0800 (PST) Received: from critter (localhost [127.0.0.1]) by critter.freebsd.dk (8.11.1/8.11.1) with ESMTP id f16Hx4B36241; Tue, 6 Feb 2001 18:59:04 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Matt Dillon Cc: Charles Randall , Dan Phoenix , Alfred Perlstein , Jos Backus , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates and qmail (RE: qmail IO problems) In-Reply-To: Your message of "Tue, 06 Feb 2001 09:50:35 PST." <200102061750.f16HoZD62214@earth.backplane.com> Date: Tue, 06 Feb 2001 18:59:04 +0100 Message-ID: <36239.981482344@critter> From: Poul-Henning Kamp Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <200102061750.f16HoZD62214@earth.backplane.com>, Matt Dillon writes: >:> softupdates disk may wind up unwinding 'more' of the last few moments >:> worth of operations then a normal filesystem would. And, I might add, >:> Reiser is the same way. >:> >:> The only way to guarentee that file data is written to disk, with any >:> filesystem no matter how it is mounted (even sync mounted filesystems), >:> is by calling fsync(). >:> >:> So I would stick with softupdates. >: >:... provided that qmail calls fsync(2). >: >:-- >:Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > > It doesn't matter whether qmail calls fsync or not as far as using > softupdates goes. No filesytem will guarentee stable storage > with fsync(), so softupdates is not going to be too much worse then > other FS's. Actually, if you don't use fsync you do loose more work with softupdates than if you use plain UFS. Softupdates can delay directory updates which plain UFS will runs synchronously, and consequently you can loose stuff you throught you had. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message