Re: Can Hypervisors have multiple image formats?

[Wido den Hollander]

On 06/26/2013 02:43 PM, Donal Lafferty wrote:
Judging by StorageManagerImpl.getHypervisorTypeFromFormat, each format can only 
be used by one Hypervisor type.

The reason I ask, is that Hyper-V 2012 supports a legacy disk image type called 
'VHD' in addition to 'VHDX'.  It's straightforward to add VHDX to the  
ImageFormat enum, but less straightforward when it comes to adding a VHD image 
type.


That is odd indeed. Any insight on this would be welcome, since I know 
that slowly QCOW3 is being worked on, so at some point we will want to 
support QCOW2 and QCOW3 for KVM.

Other then QCOW2, with RBD (Ceph) you have to use RAW since it's native 
RBD. So simply assuming that with KVM it will always be QCOW2 isn't a 
safe bet.

Wido

Any guidance would be most welcome.


E.g. from StorageManagerImpl.java

     @Override
     public HypervisorType getHypervisorTypeFromFormat(ImageFormat format) {

         if (format == null) {
             return HypervisorType.None;
         }

         if (format == ImageFormat.VHD) {
             return HypervisorType.XenServer;
         } else if (format == ImageFormat.OVA) {
             return HypervisorType.VMware;
         } else if (format == ImageFormat.QCOW2) {
             return HypervisorType.KVM;
         } else if (format == ImageFormat.RAW) {
             return HypervisorType.Ovm;
         } else {
             return HypervisorType.None;
         }
     }