Comment 26 for bug 1847105

Ok, but maybe virt-manager should then get a switch to only create it as sparse if the user wants it to be fast.
Many people use virt-manager to quickly test things, so I'd assume often disks are created, only partially used for a very short time and then thrown away.

But I agree in general and the additional fact that the "pain" only comes in if this is also on ZFS makes it maybe too special to be of high importance.