From owner-freebsd-questions@FreeBSD.ORG Mon Jan 28 16:10:13 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 D1FD6C4A for ; Mon, 28 Jan 2013 16:10:13 +0000 (UTC) (envelope-from paul@kraus-haus.org) Received: from mail-vb0-f49.google.com (mail-vb0-f49.google.com [209.85.212.49]) by mx1.freebsd.org (Postfix) with ESMTP id 952E48B2 for ; Mon, 28 Jan 2013 16:10:13 +0000 (UTC) Received: by mail-vb0-f49.google.com with SMTP id s24so1956535vbi.36 for ; Mon, 28 Jan 2013 08:10:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:subject:mime-version:content-type:from:in-reply-to:date :content-transfer-encoding:message-id:references:to:x-mailer :x-gm-message-state; bh=OsePvz6yU+lc1QNEc95bleQ5WTGb3DzZBimIx5ElYfk=; b=nm9SUsbc+RKslfikyDqa2FqDtsX2XtlU7iJMoF3izbnyskzr8zxWk8ao1psKGTmn7p Xn/mWYYOpxrH2ZRgZlomMO5jSfHwZX2s+cU/5wOuxtvKRpwmj8VcTAQVrnKlNmtVPy4S QoVVNFzlga8YrT3VRAsyme7P8RsXXMWq2t2hMY4elCqBpI6tFbQbJcDtxB5Q8l5m/AbK A/S+7I0Xe/yJ4AwdINAQle91CfdwAWdeQc7mjjJ2eyNnG16DVg+O8ryaVr9gUNzBbvLM 81rSTzfnDO6qjcCcjIQW8KPJ1HQTCAbKM2De10SFOm7KG3ft4uZAvTeoPlYegqJbtTll Nh0w== X-Received: by 10.52.180.202 with SMTP id dq10mr13435772vdc.129.1359389407484; Mon, 28 Jan 2013 08:10:07 -0800 (PST) Received: from mini1.kraus-haus.org ([96.236.21.119]) by mx.google.com with ESMTPS id y7sm6526318vdt.14.2013.01.28.08.10.05 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 28 Jan 2013 08:10:06 -0800 (PST) Subject: Re: ZFS - whole disk or partition or BSD slice? Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: text/plain; charset=us-ascii From: Paul Kraus In-Reply-To: <5105D611.4000506@ShaneWare.Biz> Date: Mon, 28 Jan 2013 11:10:04 -0500 Content-Transfer-Encoding: quoted-printable Message-Id: <7D460604-8F6B-454F-B717-678F64A75062@kraus-haus.org> References: <5105BEE4.4030402@mansionfamily.plus.com> <5105D611.4000506@ShaneWare.Biz> To: FreeBSD Mailing List X-Mailer: Apple Mail (2.1085) X-Gm-Message-State: ALoCoQkDcg1Lu9Pe/QGZIuzYFbng+n2jw/eSuLARNMTMA4D2GdsOz/eMFWgW97nmr3s/D36HT66O 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 16:10:14 -0000 On Jan 27, 2013, at 8:36 PM, Shane Ambler wrote: > I recall reading that using partitions for zfs on FreeBSD was as good = as full disks. For a boot zpool we need to at least have a partition for = the boot-code and one for zfs preventing the use of a full disk. I have been using ZFS with GPT partitions with no issues. I have = NOT compared performance between whole disk and partitioned, which is = where the difference in Solaris arises (ZFS makes better use of the = physical drive's write cache). > ZFS is meant to be compatible between different endian systems (x86 = and sparc) =46rom what I have read and heard it sounds like zpools are = expected be compatible between different OS's as well - as far as zpool = versions are compatible - but I do expect it would depend on the = partition tables being readable - while full disk usage should work I = would also think GPT is compatible. OSX 10.5 (x86 and ppc) included a = read-only zfs kext (before Apple canned the project) so it must have = been able to read Solaris or FreeBSD created zpools which does indicate = a fairly high level of compatibility. The target OS must be able to read the partitioning scheme used. = I am not aware of Solaris / OpenSolaris / Illumos being able to read GPT = partitions, but it has been over 6 months since I played with any of = them. > I believe the way ZFS marks disks/partitions with the zpool data is so = that the zpools can be recognised between systems and controllers - it = would be interesting to know if and under what conditions a zpool can be = accessed, both between different FreeBSD machines as well as the = possibility of reading on a Solaris/Indiana machine. Anyone have the = resources to test? When you give ZFS the whole disk, it writes an EFI-like label on = the drive and makes us of one partition for the ZFS data. So there *is* = a form of partitioning at the lower most layer, it is just *not* user = managed partitioning. -- Paul Kraus Deputy Technical Director, LoneStarCon 3 Sound Coordinator, Schenectady Light Opera Company