From owner-freebsd-scsi Thu Sep 21 6:38:44 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from mail-relay.eunet.no (mail-relay.eunet.no [193.71.71.242]) by hub.freebsd.org (Postfix) with ESMTP id DE10837B423; Thu, 21 Sep 2000 06:38:38 -0700 (PDT) Received: from login-1.eunet.no (login-1.eunet.no [193.75.110.2]) by mail-relay.eunet.no (8.9.3/8.9.3/GN) with ESMTP id PAA89799; Thu, 21 Sep 2000 15:38:37 +0200 (CEST) (envelope-from mbendiks@eunet.no) Received: from localhost (mbendiks@localhost) by login-1.eunet.no (8.9.3/8.8.8) with ESMTP id PAA38975; Thu, 21 Sep 2000 15:38:36 +0200 (CEST) (envelope-from mbendiks@eunet.no) X-Authentication-Warning: login-1.eunet.no: mbendiks owned process doing -bs Date: Thu, 21 Sep 2000 15:38:36 +0200 (CEST) From: Marius Bendiksen To: Stephen Byan Cc: "'Soren Schmidt'" , fs@FreeBSD.ORG, sos@FreeBSD.ORG, freeBSD-scsi@FreeBSD.ORG Subject: RE: disable write caching with softupdates? In-Reply-To: <8133266FE373D11190CD00805FA768BF055BD1D3@shrcmsg1.tdh.qntm.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > OK, I played a bit with that, the only info I can see I get from the > > higher levels is the BIO_ORDERED bit, so I tried to flush the cache > > each time I get one of those, _bad_ idea, 10% performance loss... > That's the price of having a recoverable file system. See Seltzer, Ganger, Not necessarily. > Contrast this 10% performance hit versus what you get when you disable > caching entirely. I think you will see that on some drives, this may have a greater performance impact than not caching at all. Marius To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message