From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KDbqa-0008Mf-Pb for qemu-devel@nongnu.org; Tue, 01 Jul 2008 05:08:24 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KDbqY-0008Ks-Ar for qemu-devel@nongnu.org; Tue, 01 Jul 2008 05:08:24 -0400 Received: from [199.232.76.173] (port=39438 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KDbqX-0008KC-MW for qemu-devel@nongnu.org; Tue, 01 Jul 2008 05:08:21 -0400 Received: from mail2.shareable.org ([80.68.89.115]:34508) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1KDbqW-0005eH-L7 for qemu-devel@nongnu.org; Tue, 01 Jul 2008 05:08:21 -0400 Received: from jamie by mail2.shareable.org with local (Exim 4.63) (envelope-from ) id 1KDbqS-00009h-8R for qemu-devel@nongnu.org; Tue, 01 Jul 2008 10:08:16 +0100 Date: Tue, 1 Jul 2008 10:08:16 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] "A disk read error occurred" Message-ID: <20080701090815.GA564@shareable.org> References: <478c82f00806281242q52a7fa55qcd458c9915e0c5a7@mail.gmail.com> <4867061B.2090309@qumranet.com> <20080630230542.GD20187@shareable.org> <4869F2D8.9020504@siriusit.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4869F2D8.9020504@siriusit.co.uk> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Mark Cave-Ayland wrote: > >Also, sometimes when booting the BIOS can print a disk read error > >message, and an appropriate -hdachs will fix it. I found that out > >when rebooting Windows 2000 after installing it from CD (both in > >QEMU), on a virtual disk 1GB in size. > > > >-- Jamie > > The message "A disk read error occurred" comes from the NT bootloader > when it is unable to boot, typically caused by an incorrect drive geometry. > > It sounds as if you are experiencing a similar problem to the one I > blogged about here: > http://www.ilande.co.uk/index.php?/archives/6-Migrating-an-NT4-VM-from-VMWare-to-NT4-Part-1.html. > In other words, in order to run an existing NT4 image under QEMU I had to > halve the number of heads in the NTFS BPB in order for things to work > properly. I suspect that this is a bug in either QEMU/BIOS, but I have no > idea where to even start looking. Yes, very similar, except I saw the problem _without_ migrating anything. Windows 2000 was installed _inside_ QEMU (with no special -hdachs setting) from its CD installer. It couldn't boot its own install after restarting QEMU. I looked at the partition with fdisk, then copied the c,h,s values to -hdachs... ...and QEMU said the values were out of range and refused to start! So I guessed some values which were not what fdisk reported, and it worked and booted fine. -- Jamie