Hi,

Is there a reliable way to figure out if a snapshot is in preview only using information obtained from the storage domain metadata?

I'm trying to find a way to distinguish a problematic snapshot chain (double parent) from a snapshot in preview in order to improve dump-volume chains.

Currently dump-volume-chains throws an error (DuplicateParentError) if a snapshot is in preview for the image, as there is a 'Y' shape split in the chain

with 2 volumes (previous chain + preview) pointing to a common parent:

   image:    dff0a0c0-b731-4e5b-9f32-d97310ca40de

             Error: more than one volume pointing to the same parent volume e.g: (_BLANK_UUID<-a), (a<-b), (a<-c)

             Unordered volumes and children:

             - e6c7bec0-53c6-4729-a4a0-a9b3ef2b8c38 <- 5eb2b29d-82d6-4337-8511-3c86705d566e
               status: OK, voltype: LEAF, format: COW, legality: LEGAL, type: SPARSE, capacity: 1073741824, truesize: 1073741824

             - e0475853-4514-4464-99e7-b185cce9b67d <- deceff83-9d88-4f87-8304-d5bf74d119b1
               status: OK, voltype: LEAF, format: COW, legality: LEGAL, type: SPARSE, capacity: 1073741824, truesize: 1073741824

             - e6c7bec0-53c6-4729-a4a0-a9b3ef2b8c38 <- e0475853-4514-4464-99e7-b185cce9b67d
               status: OK, voltype: INTERNAL, format: COW, legality: LEGAL, type: SPARSE, capacity: 1073741824, truesize: 1073741824

             - 00000000-0000-0000-0000-000000000000 <- e6c7bec0-53c6-4729-a4a0-a9b3ef2b8c38
               status: OK, voltype: INTERNAL, format: RAW, legality: LEGAL, type: PREALLOCATED, capacity: 1073741824, truesize: 1073741824

From the engine side it's easy, but I'd need to solve this problem using only metadata from the storage.

The only thing I could think of is that one of the volumes pointing to the common parent has voltype LEAF. Any better ideas?

Thanks,

Germano