From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] block: vpc support for ~2 TB disks Date: Thu, 15 Nov 2012 18:00:16 +0100 Message-ID: <50A51FA0.1070504@redhat.com> References: <50A0E79F0200009100082E4C@novprvoes0310.provo.novell.com> <50A2250A.4070108@redhat.com> <4B45B535F7F6BE4CB1C044ED5115CDDE012D550D234B@LONPMAILBOX01.citrite.net> <50A3C853.4010809@redhat.com> <50A4B9FB0200009100083093@novprvoes0310.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50A4B9FB0200009100083093@novprvoes0310.provo.novell.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: Charles Arnold Cc: Kevin Wolf , Thanos Makatos , "xen-devel@lists.xensource.com" , Stefano Stabellini , "qemu-devel@nongnu.org" , "stefanha@redhat.com" List-Id: xen-devel@lists.xenproject.org Il 15/11/2012 17:46, Charles Arnold ha scritto: >>> We don't use qemu's VHD driver in XenServer. Instead, we use blktap2 >>> >> to create a block device in dom0 serving the VHD file in question, >>> >> and have qemu open that block device instead of the VHD file itself. >> > >> > Yes, the question is how you handle disks bigger than 127GB, so that >> > QEMU can do the same. >> > > In analyzing a 160 GB VHD fixed disk image created on Windows 2008 R2, it appears that > MS is also ignoring the CHS values in the footer geometry field in whatever > driver they use for accessing the image. The CHS values are set at 65535,16,255 > which obviously doesn't represent an image size of 160 GB. Thanks, this would have been useful in the commit message. The patch looks good, Reviewed-by: Paolo Bonzini Paolo > This patch only extends the existing qemu driver to allow a larger image by allowing > more heads. On real hardware, only 4 bits would be allowed for heads but we don't > have that restriction in qemu.