From owner-freebsd-current Mon Apr 21 02:33:52 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id CAA02062 for current-outgoing; Mon, 21 Apr 1997 02:33:52 -0700 (PDT) Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id CAA02057 for ; Mon, 21 Apr 1997 02:33:48 -0700 (PDT) Received: (from bde@localhost) by godzilla.zeta.org.au (8.8.5/8.6.9) id TAA28976; Mon, 21 Apr 1997 19:26:28 +1000 Date: Mon, 21 Apr 1997 19:26:28 +1000 From: Bruce Evans Message-Id: <199704210926.TAA28976@godzilla.zeta.org.au> To: current@freebsd.org, imp@village.org Subject: Re: Speed deamons: How to build a build box? Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > 5) Try to have the disk geometry match the physical disks' > (although I didn't measure anything relating to doing this > or not doing this). This is bad advice. It usually makes no difference, but actually matching "the" geometry is likely to be a small pessimization, and failed attempts to match "the" geometry is likely to be a large pessimization. Most modern disks have multiple geometries, one per zone. To match them, you need a either a different slice for each geometry so that you can put the geometries in the labels and use newfs parameters -t0 -u0, or a different partition for each geometry and newfs parameters -t -u. You also need to get some of the disk latencies exactly right (if the latencies depend on the zone, then you need a slice per geometry, since the latencies aren't newfs parameters). >As you can see, the biggest pop by far came from the use of async and >noatime on both /usr/src and /usr/obj. I suspect that 5400 or 7200 I'm surprised that this makes so much difference (a factor of 2). Compilation is not very disk intensive. I didn't notice much change from using -async here (any improvement was eaten by source tree bloat :-]). Bruce