From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1Ck64n-00012Y-SV for qemu-devel@nongnu.org; Thu, 30 Dec 2004 14:35:13 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1Ck64n-00012M-Dh for qemu-devel@nongnu.org; Thu, 30 Dec 2004 14:35:13 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1Ck64n-00012J-9n for qemu-devel@nongnu.org; Thu, 30 Dec 2004 14:35:13 -0500 Received: from [66.124.73.250] (helo=marvin.brittainweb.org) by monty-python.gnu.org with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.34) id 1Ck5tc-00037Y-7C for qemu-devel@nongnu.org; Thu, 30 Dec 2004 14:23:40 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) by marvin.brittainweb.org (8.12.8/8.12.8) with ESMTP id iBUJKXrJ019798 for ; Thu, 30 Dec 2004 11:20:35 -0800 Message-ID: <41D45541.8010806@brittainweb.org> Date: Thu, 30 Dec 2004 11:21:37 -0800 From: Jason Brittain MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] HD Image Size Limits and hdachs 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 This has been asked on this list before, but wasn't answered (I've scoured the list and docs for the answer and it's not in either one): What are Qemu's limits for hard drive image files? For example, if I'm using qcow, how large of an image can I safely use, say, with Linux host & Linux guest? It seems like qemu-img lets me create pretty large images, but in a previous message Fabrice notes that the maximum parameters for the hdachs switch are: 16383,16,63[,none|lba|auto]. If I understand the math correctly, that yields a maximum of 7 gigabytes: 16383 cyls * 16 heads * 63 sectors * 512 bytes = 8455200768 total bytes, which comes out to 7Gb. BUT, I have been creating qcow images 16Gb in size, and they've been working fine (while NOT using the -hdachs startup switch). So wouldn't that mean that qemu is able to guess geometry larger than it accepts on the command line with -hdachs? If so, isn't this sort of a bug? What am I missing here? Thanks.. -- Jason "-headaches" Brittain