From owner-freebsd-stable Tue Mar 13 1:43: 9 2001 Delivered-To: freebsd-stable@freebsd.org Received: from phk.freebsd.dk (phk.freebsd.dk [212.242.86.136]) by hub.freebsd.org (Postfix) with ESMTP id 6241237B71A; Tue, 13 Mar 2001 01:43:04 -0800 (PST) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by phk.freebsd.dk (8.9.3/8.9.3) with ESMTP id KAA39262; Tue, 13 Mar 2001 10:43:02 +0100 (CET) (envelope-from phk@critter.freebsd.dk) Received: from critter (localhost [127.0.0.1]) by critter.freebsd.dk (8.11.1/8.11.1) with ESMTP id f2D9hMp05056; Tue, 13 Mar 2001 10:43:22 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Soren Schmidt Cc: bright@wintelcom.net (Alfred Perlstein), mwm@mired.org (Mike Meyer), Helge.Oldach@de.origin-it.com (Helge Oldach), oberman@es.net, mobile@FreeBSD.ORG, stable@FreeBSD.ORG Subject: Re: Disk I/O problem in 4.3-BETA In-Reply-To: Your message of "Tue, 13 Mar 2001 10:38:30 +0100." <200103130938.KAA95619@freebsd.dk> Date: Tue, 13 Mar 2001 10:43:22 +0100 Message-ID: <5054.984476602@critter> From: Poul-Henning Kamp Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <200103130938.KAA95619@freebsd.dk>, Soren Schmidt writes: >It seems Alfred Perlstein wrote: >> >> Having write caching on is like having the disk ignore _any_ >> filesystem's attempt to do softupdates/logging/delayed-order-writes >> because the disk _lies_ to the OS about when a write is safely on >> the disk. > >Hmm, I think the problem here is that the OS doesn't tell the >drivers WHEN it expects to have data written to disk, I can't >see why it should not be possible to have even softupdates >say "now before I write this I expect everything so far to >be on disk". I think it can be done really easy: Whenever a sync(1) is executed and every 30 seconds a flush should be sent. -- 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-stable" in the body of the message