From owner-freebsd-stable@FreeBSD.ORG Mon Jul 28 17:16:53 2003 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4D7DE37B401 for ; Mon, 28 Jul 2003 17:16:53 -0700 (PDT) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2FB4543F3F for ; Mon, 28 Jul 2003 17:12:52 -0700 (PDT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (localhost [127.0.0.1]) by fledge.watson.org (8.12.9/8.12.9) with ESMTP id h6T0C0ai070864 for ; Mon, 28 Jul 2003 20:12:00 -0400 (EDT) (envelope-from robert@fledge.watson.org) Received: from localhost (robert@localhost)h6T0Aegg070858; Mon, 28 Jul 2003 20:12:00 -0400 (EDT) Date: Mon, 28 Jul 2003 20:10:39 -0400 (EDT) From: Robert Watson X-Sender: robert@fledge.watson.org To: Chris Howells In-Reply-To: <200307281634.39887.lists@chrishowells.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-stable@FreeBSD.ORG Subject: Re: Large hard disk support in FreeBSD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Jul 2003 00:16:53 -0000 On Mon, 28 Jul 2003, Chris Howells wrote: > I'd like to put a 60GB hard disk into Gateway 2000 Pentium 150 (from '96 > or '97 or so I think) running FreeBSD 4.8 RELEASE. > > Can anybody tell me how successful this is likely to be? Will I be able > to use the full capacity of the drive? > > I seem to recall that the trick with large hard disks and old BIOSes is > to disable the drive in the BIOS and let the OS detect the disk > itself... is this the case with FreeBSD as well? Up until relatively recently, my main personal web service box was a Gateway 2000 P120 from '95 running FreeBSD 4.x, so I can speak to this with some confidence :-). There are a few things you need to look at: (1) BIOS revision. Make sure you've flashed your BIOS forward as far as possible -- some older Gateway 2000 BIOS's will hang if they see a driver larger than they think is possible (I'm sure there's a better technical definition, but the result is clear regardless :-). (2) Do you want to boot from the drive? If I might suggest--don't even try. Boot from a drive known to work fine with the BIOS. As you suggest above, leave the drive unprobed (disabled) in the CMOS configuration, which will help prevent the BIOS from tripping over it. this will mean you can't use the drive in the loader before the kernel is loaded, but since FreeBSD's device probing and management is pretty much independent of the BIOS, it should work fine with FreeBSD. (3) The ATA controller built into your motherboard may not support larger disk addressing, although I think that shouldn't be a problem with 60GB. If you try to use a drive larger than addressable using the ATA controller, you may want to pick up a cheap PCI ATA controller (or get the "kit" version of the drive that has a new controller). (4) Cabling and support for non-PIO. I found that my older motherboard's ATA controller had problems negotiating higher rate transfers from the disk, so ended up disabling the DMA support for at least one of the drives I added. You will probably also want to make sure you're using the newer cable that will come with any recent drive, since that will help avoid quality and negotiation problems. You might end up needing to force PIO support anyway if you're getting occasional timeouts from the drive. That said, I ran just fine for about 8 years on my p120 -- I didn't want to take it out of service, but I needed more memory than the chipset could comfortably support. Some of those systems can only cache the first 64MB of memory, so any additional memory is used uncached. I ended up upgrading it to an E-Machine, go figure :-). The old p120 is now back at home from colocation, and I'm sure I'll find a use for it at some point. Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert@fledge.watson.org Network Associates Laboratories