I am created a new Disk snapshot in VM
Versions of the related components and OS (frontend, hypervisors, VMs): Opennebula 5.2,KVM,Centos 7
Steps to reproduce: Created disk snapshot i tried to delete, but cannot able to delete.
Current results: 
Expected results: Then what is the use of delete in disk snapshot.
-bumping this post/same problem here-
In oned.conf edit TM_MAD directive and change ALLOW_ORPHANS = NO to ALLOW_ORPHANS = YES.
Or upgrade ONe and for current VMs check paramater /VM/SNAPSHOTS/ALLOW_ORPHANS
and change it to YES.
e.g.
# For example to change ALLOW_ORPHANS=YES on DISK_ID=0 of VM_ID=23
# you should repeat for each disk in the VM metadata
onedb change-body vm --id 23 '/VM/SNAPSHOTS[DISK_ID=0]/ALLOW_ORPHANS' -- "YES"
Do you know what version of Opennebula supports this ?
OpenNebula 5.4.x