From owner-freebsd-questions@FreeBSD.ORG Thu Sep 28 07:10:33 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E157F16A407 for ; Thu, 28 Sep 2006 07:10:33 +0000 (UTC) (envelope-from adamlsd@gmail.com) Received: from wx-out-0506.google.com (wx-out-0506.google.com [66.249.82.230]) by mx1.FreeBSD.org (Postfix) with ESMTP id E8F3743D77 for ; Thu, 28 Sep 2006 07:10:28 +0000 (GMT) (envelope-from adamlsd@gmail.com) Received: by wx-out-0506.google.com with SMTP id i27so478350wxd for ; Thu, 28 Sep 2006 00:10:28 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:in-reply-to:references:mime-version:content-type:message-id:content-transfer-encoding:cc:from:subject:date:to:x-mailer:sender; b=GvtB+kPuUx208WQzx+gHPZzExjv2iQfuW2e7vBz5dppjREKdl4dtEmX2jebMtI1Kqjmn1Li2HjZshz5G6/guSe380HuGcwjT5RswT4yiC857VuSnZw6nLDya+ERfZFNAyIAcQiD7FzqNZwOKzXGsoQUDhCR5xH+caqpaZVv2SlM= Received: by 10.70.113.5 with SMTP id l5mr2316118wxc; Thu, 28 Sep 2006 00:10:28 -0700 (PDT) Received: from ?130.245.126.51? ( [130.245.126.51]) by mx.gmail.com with ESMTP id i17sm1949868wxd.2006.09.28.00.10.28; Thu, 28 Sep 2006 00:10:28 -0700 (PDT) In-Reply-To: References: Mime-Version: 1.0 (Apple Message framework v624) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <1e426d7180c9ec17a6c2472f1f3921c3@FreeBSD.org> Content-Transfer-Encoding: 7bit From: Adam Martin Date: Thu, 28 Sep 2006 03:10:27 -0400 To: Jeffrey Katz X-Mailer: Apple Mail (2.624) Sender: Adam Martin Cc: freebsd-questions@freebsd.org Subject: Re: nested labels X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Sep 2006 07:10:34 -0000 On 2006 Sep 28 , at 01:08, Jeffrey Katz wrote: > Adam Martin's discussion of nested partitions was very enlightening > and useful. A nice thing about the approach is that it can be used on > a "dangerously dedicated" hard drive. Well, it merely takes advantage of GEOM. You can even nest GPTs, and other things inside of BSD labels, and vice versa. The most important thing to keep in mind is that every time that you create a new "device" from partitioning a device, GEOM allows you to install partitioning tables on them, and make more "devices" from those. As can be seen from my absurd case. That said, there are many good reasons to avoid over-partitioning a drive. Data can become more difficult to organize, as various filesystems have limited space, and start filling up at different rates. Also, failures in the sectors that contain the partitioning tables will cause you to have great difficulty in reconstructing data, in the event of disc failures. Don't over abuse nested partitions. I like to keep a paper copy of the actual sizes of all the entities in my partition tables, and their offsets, and mountpoints. At least once, this knowledge has helped me recover from serious disc failure. With the advent of half-terabyte, and larger drives, we're nearing the upper bounds of 32-bit bounded filesystems, and partitioning tables. GPTs are supposedly able to handle larger volumes than 2TB. Keep an eye on the freebsd large disc project: http://www.freebsd.org/projects/bigdisk/index.html Cheers, -- Adam David Alan Martin