From owner-freebsd-fs@FreeBSD.ORG Tue Dec 22 02:48:31 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 59908106568B for ; Tue, 22 Dec 2009 02:48:31 +0000 (UTC) (envelope-from benschumacher@gmail.com) Received: from mail-pw0-f44.google.com (mail-pw0-f44.google.com [209.85.160.44]) by mx1.freebsd.org (Postfix) with ESMTP id 2EB3A8FC0A for ; Tue, 22 Dec 2009 02:48:30 +0000 (UTC) Received: by pwi15 with SMTP id 15so3877937pwi.3 for ; Mon, 21 Dec 2009 18:48:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=2gpsTgaEay9y4KSMfa7K9kJCshxjw9xjXZ+TkBo6io8=; b=aw+/RBfzzF09tXkeFpwCBjECmsvCluNIe5h4O3TaADKUa7PUW4aiwVhI607m3P88uX aZ+ostSZkVw3shCTCkUzH1AXHZJexpYii4g5FNlaYyMy9S2XO4u9Yt9m3jwXz5tfOZof R5VWoKW6CjFXjV8msjF9cLXCVudtntUajIx5k= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=vJI0N+ly0zODZy2lSY0h99QOkzyF7plHc/S5S/uU6Yolfp1cT/D72P3k0+dFFXByuZ tufCRrgQRkldq3iAGBthgORNRoUhXc/kDEYRpZJ/vrcmAmiKWJAl71sCRDTFpnxAeG4F aIClByue2s95tv5PDiEtZ4LE5a3gzCkzWEI8w= MIME-Version: 1.0 Received: by 10.143.26.41 with SMTP id d41mr3266594wfj.13.1261450110557; Mon, 21 Dec 2009 18:48:30 -0800 (PST) In-Reply-To: <4B302A6D.3000408@modulus.org> References: <712903.15604.qm@web113517.mail.gq1.yahoo.com> <3612709F-15CA-4A59-86B1-2674BAA2936D@gmail.com> <240049.46806.qm@web113517.mail.gq1.yahoo.com> <4B302A6D.3000408@modulus.org> Date: Mon, 21 Dec 2009 19:48:30 -0700 Message-ID: <9859143f0912211848n447183dfs7e0e4bd02e52c5ad@mail.gmail.com> From: Ben Schumacher To: freebsd-fs Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: Plans for Logged/Journaled UFS X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Dec 2009 02:48:31 -0000 On Mon, Dec 21, 2009 at 7:09 PM, Andrew Snow wrote: > Is there any provision to put the journal on a seperate device? =C2=A0Thi= s can > solve the performance degradation issue. I'm not sure that would provide much more reliability, however. If you're adding a second device to use the journal you risk losing data if either device fails... given how small the data is (I believe 32 bytes per entry), I'm not sure it's really worthwhile. Most of what I've read in the past about FreeBSD's FS interactions seems to imply that the lower-level (ATA-layer) is not terribly optimized for larger drives and faster interfaces available these days. I'm sure I could go Google up some references, but I think it's been well covered in the past. Cheers, Ben