On Fri, 19 Mar 2010, Manuel Bouyer wrote:
On Fri, Mar 19, 2010 at 04:44:58PM +0100, Mark Weinem wrote:Hi, which virtual disk formats does Xen 3.3.x support? And how well does it work? Wikipedia.org states VMDK and VHD as natively supported formats: http://en.wikipedia.org/wiki/Virtual_disk_image But I could not find anything about the support in the Xen documentation nor the Xen wiki.The disk format is a direct 1:1 mapping beteen disk blocks of the virtual disk and blocks in the underlying file in dom0; there's no transformations, not even an offset.
Blocks in the underlying device surely? vnd(4) is used to present the file as a block device.
I'm not sure which virtual disk "format" in the above page this translates to.
It doesn't map to either of those (VMDK being VMware and VHD being Microsoft/XenServer). If vnd was extended to support other formats rather than 1:1 mapping then it would work. I know one developer has extended vnd(4) to support vhd files and then went onto develop libvdisk which allows a userspace program to do the translation (using pud(4)). I'm not sure of the status of this, so I won't name him.
-- Stephen