From owner-freebsd-current@FreeBSD.ORG Thu Feb 17 08:08:47 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5302E16A4CE; Thu, 17 Feb 2005 08:08:47 +0000 (GMT) Received: from watery.cc.kogakuin.ac.jp (watery.cc.kogakuin.ac.jp [133.80.152.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7A42F43D48; Thu, 17 Feb 2005 08:08:46 +0000 (GMT) (envelope-from nyan@jp.FreeBSD.org) Received: from localhost (localhost [IPv6:::1])j1H88K6D034320; Thu, 17 Feb 2005 17:08:25 +0900 (JST) (envelope-from nyan@jp.FreeBSD.org) Date: Thu, 17 Feb 2005 17:08:03 +0900 (JST) Message-Id: <20050217.170803.74725228.nyan@jp.FreeBSD.org> To: imp@bsdimp.com From: Takahashi Yoshihiro In-Reply-To: <20050216.085534.128329712.imp@bsdimp.com> References: <20050215.135815.112575021.imp@bsdimp.com> <20050216.131604.41667980.nyan@jp.FreeBSD.org> <20050216.085534.128329712.imp@bsdimp.com> X-Mailer: Mew version 4.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit cc: freebsd-stable@freebsd.org cc: freebsd-current@freebsd.org cc: nakaji@jp.FreeBSD.org cc: sos@DeepCore.dk Subject: Re: UPDATE: ATA mkIII first official patches - please test! X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Feb 2005 08:08:47 -0000 In article <20050216.085534.128329712.imp@bsdimp.com> "M. Warner Losh" writes: > I see. Let me see if I understand the implications: > > (1) This disk won't interoperate with other OSes on the pc98 > machine because the pc98 partition format specifies things > in terms of CHS, but doesn't specify an actual geometry. I don't test it yet, but I think it is no problem if right geometry translation is done. > (2) Further, since dp_scyl and dp_ecyl are both 16bits, we are > limited to 65535 cylinders. The above geometry of 387621 > violates this assumption. So you can really only use > 66059280 of the 390721968 sectors on this disk (or about 17%). I tried to use the disk with 16H/63S geometry but I cannot at all. It seems that the fdisk and/or disklabel write to strange place. > (3) It is insufficent to fix this in geom_pc98 because that is > not used until after the partition is placed on the disk > and fdisk_pc98 needs the geometry to place that partition. Yes. > (4) This only impacts newer ATA6 disks. ATA5 and older appear > to be working properly. ata6 disks need some other > mechanism to get this information, correct? Probably... I am sure that ATA6 disks at least need to get a geometry information from PC98 BIOS. > When I asked about the 'get the geometry from the BIOS' patches that > are circulating, I was told that it was hard to match the FreeBSD > device to the BIOS table. I think that it is hard to get a right geometry in all cases, many extended ATA cards are used, but it succeeds mostly. --- TAKAHASHI Yoshihiro