From owner-freebsd-questions Mon Aug 13 8: 5:48 2001 Delivered-To: freebsd-questions@freebsd.org Received: from ptavv.es.net (ptavv.es.net [198.128.4.29]) by hub.freebsd.org (Postfix) with ESMTP id BA68437B406 for ; Mon, 13 Aug 2001 08:05:44 -0700 (PDT) (envelope-from oberman@ptavv.es.net) Received: from ptavv.es.net (localhost [127.0.0.1]) by ptavv.es.net (8.10.1/8.10.1) with ESMTP id f7DF5dR30168; Mon, 13 Aug 2001 08:05:39 -0700 (PDT) Message-Id: <200108131505.f7DF5dR30168@ptavv.es.net> To: "Kevin Hui - DCS" Cc: "Alfred Perlstein" , freebsd-questions@FreeBSD.ORG Subject: Re: Experiencing very slow raw write speeds on /dev/ad1 In-reply-to: Your message of "Sun, 12 Aug 2001 23:02:27 EDT." <003401c123a4$63e5d560$07010101@mtwx1.on.home.com> Date: Mon, 13 Aug 2001 08:05:39 -0700 From: "Kevin Oberman" Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > From: "Kevin Hui - DCS" > Date: Sun, 12 Aug 2001 23:02:27 -0400 > > Correct me if I'm wrong, but I do not think that turning (1) and (2) on > would matter in this case since they are both for file-system-level > performance tuning. I am access the raw device here, bypassing the > file-system layer. Right you are! I'm afraid I missed that obvious detail. In your case I believe enabling write cache is about all that can be done. I wonder if the lack of "raw" disk partitions on FreeBSD might be an issue here. (Yes, the raw devices are still there, but there is no longer any difference between them and the "cooked" devices.) This is a bit beyond my expertise. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message