From owner-freebsd-stable Fri Sep 21 10:54:18 2001 Delivered-To: freebsd-stable@freebsd.org Received: from probity.mcc.ac.uk (probity.mcc.ac.uk [130.88.200.94]) by hub.freebsd.org (Postfix) with ESMTP id B0E2437B406 for ; Fri, 21 Sep 2001 10:54:14 -0700 (PDT) Received: from dogma.freebsd-uk.eu.org ([130.88.200.97] helo=dogma) by probity.mcc.ac.uk with esmtp (Exim 2.05 #7) id 15kUVA-000FsE-00; Fri, 21 Sep 2001 18:54:12 +0100 Received: (from jcm@localhost) by dogma (8.11.4/8.11.1) id f8LHsCe82000; Fri, 21 Sep 2001 18:54:12 +0100 (BST) (envelope-from jcm) Date: Fri, 21 Sep 2001 18:54:11 +0100 From: j mckitrick To: Matt Dillon Cc: Mike Meyer , "Daniel O'Connor" , Kevin Oberman , stable@freebsd.org Subject: Re: RE: hw.ata.wc && hw.ata.tags && softupdates short question Message-ID: <20010921185411.C81649@dogma.freebsd-uk.eu.org> References: <200109210329.f8L3TGR30860@ptavv.es.net> <20010920211704.C7820@gateway.bogus> <15274.48864.994229.51687@guru.mired.org> <200109210549.f8L5n6r67664@earth.backplane.com> <20010921122805.A78591@dogma.freebsd-uk.eu.org> <200109211726.f8LHQ3h70907@earth.backplane.com> <20010921183212.A81649@dogma.freebsd-uk.eu.org> <200109211736.f8LHaGO71153@earth.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <200109211736.f8LHaGO71153@earth.backplane.com>; from dillon@earth.backplane.com on Fri, Sep 21, 2001 at 10:36:16AM -0700 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG | You can choose one or the other, neither, or both. I typically run my | laptop with softupdates turned on and write caching also turned on. A | somewhat safer configuration would be softupdates turned off and write | caching turned on, but not because softupdates and write caching might | conflict. They don't. Only because softupdates itself delays meta-data | I/O and more work can be lost if a crash occurs then otherwise. Without knowing the details, I was just trying to sort out the tradeoffs of each option. We've been told softupdates is reliable and makes UFS about as fast as Linux ext2fs. We've been told write caching turned OFF causes a huge performance hit, but ON can cause data loss. And we've also heard that some controllers tell you WC is off even when it is still on. When you put it all together, it makes quite an interesting fuzzy-logic truth table. :-) jm -- My other computer is your windows box. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message