From owner-freebsd-questions@FreeBSD.ORG Mon Jan 28 06:05:11 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id BE94F721 for ; Mon, 28 Jan 2013 06:05:11 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: from mail-ob0-f177.google.com (mail-ob0-f177.google.com [209.85.214.177]) by mx1.freebsd.org (Postfix) with ESMTP id 7038FAB6 for ; Mon, 28 Jan 2013 06:05:11 +0000 (UTC) Received: by mail-ob0-f177.google.com with SMTP id wc18so1119056obb.36 for ; Sun, 27 Jan 2013 22:05:05 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type:x-gm-message-state; bh=lESpRgIe2ErA9H7RmNhmg5mwpsrV5cVPeXw6eubH+OA=; b=IPA/u1luaV9FSIL2y+c+rcsKE+R6H6dvbSml+BuUftNSNLk9qLOv8XZJGs+r8kOcjl mF8jz9QEMGGz14yzqjMH+fgRZRlRN9xHehqhRkaZKfWZaKMrtElJKAq5yUQdPeupl2MV N3+3nd0jLFo+16d5gp++wAET129VUqG/dNi2/baAuUlpXK8V48RC1LdDWkPBThxhzAO5 mBz80v5VXf1oO+Uz/c0bYmxNBIzo95TMkn8XgR40mlFEqdIfChhWWpAav9mMD/oKNCjz nqbfRjqE/yLFejfks7M8aqpFUCw+CsJqzu2la9RpjJLwow5pi4dosrJins9BrbTTGUJ9 GS5g== MIME-Version: 1.0 X-Received: by 10.60.19.161 with SMTP id g1mr10551149oee.117.1359353105509; Sun, 27 Jan 2013 22:05:05 -0800 (PST) Received: by 10.60.60.10 with HTTP; Sun, 27 Jan 2013 22:05:05 -0800 (PST) In-Reply-To: <5105D611.4000506@ShaneWare.Biz> References: <5105BEE4.4030402@mansionfamily.plus.com> <5105D611.4000506@ShaneWare.Biz> Date: Sun, 27 Jan 2013 22:05:05 -0800 Message-ID: Subject: Re: ZFS - whole disk or partition or BSD slice? From: Michael Sierchio To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQl9dNIDujoTYojuVGgf+c4G8ATqjcujMwSADONts+P7rhJNlmwxXKrn1LgCSAIUIe0+wD9S X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Jan 2013 06:05:11 -0000 On Sun, Jan 27, 2013 at 5:36 PM, Shane Ambler wrote: > I recall reading that using partitions for zfs on FreeBSD was as good as > full disks. No, it isn't - ZFS can fully utilize disk caches when presented with whole devices. There are possible reasons to create partitions - one being that if an unfriendly OS sees the device, it won't try to initialize it if it sees a partition map. Another is using a cheap RAID controller that can't be fully disabled - in which case you generally need to create a partition that doesn't include the last few sectors of the disk, where such controllers keep magic data. - M