From owner-freebsd-questions@FreeBSD.ORG Mon Aug 25 03:23:12 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 9D8B1D3A for ; Mon, 25 Aug 2014 03:23:12 +0000 (UTC) Received: from wonkity.com (wonkity.com [67.158.26.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "wonkity.com", Issuer "wonkity.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 498BA360E for ; Mon, 25 Aug 2014 03:23:12 +0000 (UTC) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.14.9/8.14.9) with ESMTP id s7P3NAf4032322 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sun, 24 Aug 2014 21:23:10 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.14.9/8.14.9/Submit) with ESMTP id s7P3NArY032319; Sun, 24 Aug 2014 21:23:10 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Sun, 24 Aug 2014 21:23:10 -0600 (MDT) From: Warren Block To: Michael Sierchio Subject: Re: some ZFS questions In-Reply-To: Message-ID: References: <201408070816.s778G9ug015988@sdf.org> <40AF5B49-80AF-4FE2-BA14-BFF86164EAA8@kraus-haus.org> <201408211007.s7LA7YGd002430@sdf.org> <201408241015.s7OAFRv7010196@sdf.org> <20140825014249.GA28995@neutralgood.org> User-Agent: Alpine 2.11 (BSF 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (wonkity.com [127.0.0.1]); Sun, 24 Aug 2014 21:23:11 -0600 (MDT) Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Aug 2014 03:23:12 -0000 On Sun, 24 Aug 2014, Michael Sierchio wrote: > On Sun, Aug 24, 2014 at 8:00 PM, Warren Block wrote: >> On Sun, 24 Aug 2014, Michael Sierchio wrote: >> >>> On Sun, Aug 24, 2014 at 6:42 PM, wrote: >>> >>> >>>> If you can use GPT partitioning then you can have GPT labels on >>>> partitions >>>> spanning entire disks. Then you can rearrange physical disks to your >>>> hearts >>>> content. >>>> >>>> The bonus is that you can put identifying information in the label name >>>> to be even more sure you are replacing the correct disk when the time >>>> comes. >>> >>> >>> You can do this - and it's the approach that FreeNAS takes, but you >>> lose the benefits of presenting a whole disk to ZFS - the ability to >>> fully use the disk cache when presented a raw device rather than a >>> partition. >> >> >> I thought that was a Solaris-only limitation. In fact, I'm pretty sure it >> is, and does not apply on FreeBSD. > > You mean Solaris-only benefit? No, I mean that the disk cache problem was only on Solaris, and does not apply to FreeBSD. On FreeBSD, there is no difference in performance between partitions versus the whole disk.