1. A method, comprising: creating a volume on a computer storage device in a namespace environment with a hierarchy of multiple namespaces including a trunk namespace; generating a plurality of instantiations of the volume in the namespace environment; maintaining a junction table having a plurality of entries; associating, in a first entry of the junction table, a first instantiation of the volume with a parent namespace having a parent namespace identifier and a first child namespace having a first child namespace identifier, wherein the namespace environment with the hierarchy of multiple namespaces includes the parent namespace and first child namespace; associating, in a second entry of the junction table, a second instantiation of the volume with the parent namespace having the parent namespace identifier and a second child namespace having a second child namespace identifier, thereby having the first and second instantiations of the volume appear in multiple namespaces in the namespace environment with the hierarchy of multiple namespaces that include the second child namespace; and storing, in the junction table having the plurality of entries, restricting values of namespace identifiers such that an instantiation of the volume cannot become its own ancestor within the hierarchy of multiple namespaces, wherein the restricting values require that if the instantiation of the volume is in the trunk namespace, the parent namespace identifier and child namespace identifier for the instantiation of the volume equal a trunk namespace identifier of the trunk namespace.