Machine implemented method for generating and accessing a point in time copy of an expandable storage volume in a network storage system is provided. The expandable storage volume includes a namespace for storing information for accessing data objects stored at a plurality of data constituent volumes managed by a plurality of nodes of the storage system. The method includes initiating a logical fence first for the namespace and then for the data constituent volumes for generating the point in time copy of the expandable storage volume. The logical fence filters out any information written after the fence is initiated from the point in time copy of the expandable storage volume.