I have a VM whose root disk in on zone-wide, managed storage.
When I go to migrate the VM to a host in another cluster, the GUI correctly points out that to migrate the VM to the desired host that storage migration will be required.
Since I am good with both the VM and its disk being migrated, I initiate the action.
The GUI ends up invoking the migrateVirtualMachine API command instead of the migrateVirtualMachineWithVolume API command, which causes the process to fail. The process does fail gracefully (nothing seems to be left in a bad state).
If I invoke the migrateVirtualMachineWithVolume API command from CloudMonkey and pass in the necessary parameters, the migration is successful.
I know this used to work from the GUI at some point in 4.10 development because I recorded a video demonstrating this feature as executed from the GUI: