Hi All,

I've been working on a bit of functionality for the engine that will allow a 
user to query a domain for new disk images (GetUnregisteredImagesQuery) for 
which the engine was previously unaware and a separate command to register 
those images (ImportImageCommand). These commands will be exposed through the 

This functionality is needed as we are developing an extension/plugin to oVirt 
that will allow a NetApp storage controller to handle cloning the actual disks 
outside of oVirt and need to import them once they are cloned. We'll be using 
other existing APIs to attach the disk to the necessary VM once the disk is 
cloned. On the NetApp side, we'll ensure the disk is coalesced before cloning 
so as to avoid the issues of registering snapshots.

GetUnregisteredImagesQuery will be accessible through the disks resource 
collection on a storage domain. A "disks" resource collection does not yet 
exist and will need to be added. To access the unregistered images, a parameter 
(maybe "unregistered=true") would be passed. So the path to "GET" the 
unregistered disk images on a domain would be something like 
 This will return a list of disk images that can be each used as input to the 
ImportImageCommand to get them added to oVirt.

ImportImageCommand will be accessible through "POST"ing a disk to 
/api/disks?import=true. The disk will be added to the oVirt DB based on the 
information supplied and afterward would be available to attach to a VM.

When querying for unregistered disk images, the GetUnregisteredImagesQuery 
command will use the getImagesList() VDSM command. Currently this only reports 
the GUIDs of all disk images in a domain. I had been using the getVolumesList() 
and getVolumeInfo() VDSM commands to fill in the information so that valid disk 
image objects could be registered in oVirt. It seems these two functions are 
set to be removed since they are too invasive into the internal VDSM workings. 
The VDSM team will need to either return more information about each disk as 
part of the getImagesList() function or add a new function getImageInfo() that 
will give the same information for a given image GUID.

Note that much of this work had originally been submitted under patch 
http://gerrit.ovirt.org/#/c/9603/. After several reviews it was found to be 
lacking in its design and was using deprecated APIs that did not yet have 
replacements. I'm reworking the code now to conform to this design and asking 
for further input from the VDSM, core, and restapi teams to ensure we can get 
this done quickly and correctly as it is needed for the 3.2 release.


Chris Morrissey
Software Engineer
NetApp Inc.

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