From owner-freebsd-questions@FreeBSD.ORG Mon Feb 8 20:10:39 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BB4511065672 for ; Mon, 8 Feb 2010 20:10:39 +0000 (UTC) (envelope-from bf1783@googlemail.com) Received: from mail-fx0-f226.google.com (mail-fx0-f226.google.com [209.85.220.226]) by mx1.freebsd.org (Postfix) with ESMTP id 4EF3A8FC12 for ; Mon, 8 Feb 2010 20:10:38 +0000 (UTC) Received: by fxm26 with SMTP id 26so1049695fxm.13 for ; Mon, 08 Feb 2010 12:10:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:reply-to:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=4sJCCuOOk36wOhnwXl9GzyNBtBXks+oY33cmxhJrWPg=; b=Kkycz/kNqHMv8ZnMacTpGCtuFbMzKNEpXhLpDiajk++d7CFKgQYU15UdQDFdy2HCXC Y0KAZnBxxbQfhR+2K85goNzUW1DyrLVLmSCkxsrwcZaSM+esZZVlquwF+q+/cck8Dx5E EsTKlopr1MoeeZLfV7yMG6cxepTza/ZPGb2nE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; b=CZQ4YbEejEVosiGc2V5kwasXWA0sMuSc/jciOC/b+14Dnohfsu2pqhKwA1+1y7eAEl QKqARBagdrCdRBDcs5etGRXxlOzwQrvTLJqkP1g2NEvaSF9n5Od2ypvpE1+YWquNYd1b 33PLdKJAx0C6vYG9uwOl5gByhFe9Ot3aRSAhQ= MIME-Version: 1.0 Received: by 10.216.85.14 with SMTP id t14mr95783wee.222.1265659837698; Mon, 08 Feb 2010 12:10:37 -0800 (PST) In-Reply-To: <20100208200444.GA58228@gizmo.acns.msu.edu> References: <20100208200444.GA58228@gizmo.acns.msu.edu> Date: Mon, 8 Feb 2010 15:10:37 -0500 Message-ID: From: "b. f." To: Jerry McAllister Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-questions@freebsd.org Subject: Re: Should root partition be first partition? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: bf1783@gmail.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Feb 2010 20:10:39 -0000 On 2/8/10, Jerry McAllister wrote: > On Mon, Feb 08, 2010 at 02:37:30PM -0500, b. f. wrote: > >> > You can even >> >leave gaps between partitions if you want, but that is pretty crazy >> >since it just wastes some of the available space. >> > >> >There have been quite a lot of recommendations on how to lay out a disk >> >for best performance, based on the observation that disk access times >> >vary depending on how far away the data is from the spindle, and the >> >expected usage patterns for the partition. Like any such advice, it >> >has tended to become less valid over time. Modern disks really don't >> >have any physical meaning to the Cylinder/Head/Sector style addressing >> >schemes[*] nowadays -- and you're pretty much bound to be using LBA >> >style addressing anyhow. Also, machines nowadays have so much RAM that >> >(a) swap is hardly ever used and (b) access to popular files is >> >frequently answered out of VM caches rathe than needing disk IO. >> >> >> Layout is still important, and leaving some blank space may not be so >> crazy. Here I'm thinking not so much of ordering (although one would >> probably be best served by the recommended default ordering), but of >> alignment, size, raid/stripe/concat configuration, and file system >> block and fragment size selection. Witness the (as much as tenfold) >> performance difference from simple changes, highlighted in the recent >> thread entitled 'File system blocks alignment' on freebsd-arch@ during >> December 2009 - January 2010, beginning with: >> >> http://lists.freebsd.org/pipermail/freebsd-arch/2009-December/009770.html >> >> If you're laying out a new disk, you may as well take a few minutes >> and get the most out of it, even if you're not going to invest in a >> lot of new hardware. > > The system nowdays does all that figuring for you and manages > boundaries reasonably. > > ////jerry > That does not seem to be the conclusion of those who contributed to the thread I cited, although "reasonably" is open to interpretation.